Let's start off with the phone. Like many of the latest Android flagships, the PadFone Infinity comes with a 5-inch, 1080p display and a quad-core chip. In terms of resolution, viewing angle and color gamut, the newer screen is a significant upgrade from the predecessor's 4.7-inch, 720p panel; though the screens from both generations belong to Sharp's LTPS line (not to be confused with the newer IGZO line, which is currently less efficient at this panel size). Unsurprisingly, the Infinity comes with a bigger built-in battery -- 2,400mAh, which is a nice bump from the old 2,140mAh cell. The main camera uses the same Sony 13-megapixel IMX091 sensor as the PadFone 2, but its lens has been upgraded from f/2.4 to a brighter f/2.0. On the other side of the phone, the old 1.2-megapixel front-facing camera has been replaced by a 2-megapixel, f/2.0 module (it's an OmniVision OV2722 sensor, if you care), but the backlit capacitive soft keys below the screen are here to stay.
The Infinity utilizes a brand-new design that takes advantage of an aerospace-grade, twice-anodized aluminum alloy construction. Instead of the signature Zen-ripple etching on the old polycarbonate cover, the almost fully metallic Infinity features a vertical brush pattern across its back -- one that is ever so slightly curved when viewed from either the top or bottom, making the thickness vary from 8.9mm in the middle to about 6mm at the edges.
The back side alone easily makes this one of the best-looking devices ASUS has ever created.
While the back's gentle curve does make for a somewhat comfortable grip, it stops dead at the straight sides and therefore produces relatively sharp edges. The two previous PadFones, on the other hand, had well-rounded corners that fit our hands better. It would have also helped if the screen bezels were less than 4mm thick, thus keeping the phone narrower. However, these are trade-offs that we're willing to accept for the sake of the Infinity's versatility, solid feel and clean look. How clean? The back is dominated by the straight brushed-metal pattern, though there are a few features garnishing it as well. Near the top you'll find the usual camera and its LED light, then at the bottom there's the "PadFone" logo above a T-shaped NFC antenna band -- a feature seen on some metallic phones like the Xperia Ion, Xperia P and the HTC One. The back side alone easily makes this one of the best-looking devices ASUS has ever created. As for the front, the protruding, scratch-resistant Corning screen lens covers almost the entire surface, leaving a shiny 1mm-wide chamfer from each side of the metallic body to reduce the chance of shattering when dropped.
The phone's four sides feature a matte finish in the same color as the back -- either "titanium gray," "hot pink" or "champagne gold" (color availability may vary across regions). Interestingly, the loudspeaker's now located on the right side just above the power button and volume rocker, so it's less likely to be blocked in various scenarios. On the other side of the phone you'll only find a pin-ejection tray for a nano-SIM card, which makes the Infinity the first non-Apple device to adopt the new standard (the fake iDevices don't deserve recognition here, obviously).
The top and bottom sides actually consist of well-disguised polycarbonate, which enables better reception through what's otherwise an all-metal body. The top edge is occupied only by a 3.5mm headphone jack, whereas the bottom side houses the microphone and a micro-USB socket. Unlike the PadFone 2, which had a 13-pin MHL connector, the Infinity's micro-USB port integrates the MyDP (Mobility DisplayPort) interface for twice the performance of MHL (at 5.4Gbps, which allows 1080p60 playback). It also provides a snug fit with any ordinary micro-USB plug -- something that the PadFone 2 failed at. Finally, sandwiching the micro-USB port are two round sockets for the tablet module's external antenna, catering to cellular signal (worldwide model: WCDMA 900 / 2100 with DC-HSPA+, and LTE 800 / 1800 / 2100 / 2600) as well as Bluetooth 4.0 and 802.11a/ac/b/g/n.
What you won't find on the Infinity is a slot for microSD expansion, so you'll have to choose carefully between the 32GB and 64GB models. But as with the PadFone 2, ASUS offers 50GB of cloud storage, free for two years. Plus, there's always the handy, but less elegant USB OTG for storage expansion via flash drives.
In principle, the hardware here is more similar to the PadFone 2 than the original PadFone: the phone docks vertically into an exposed bay on the back of a 10.1-inch tablet module aka the PadFone Station. And unlike the first PadFone, there's still no docking keyboard with a built-in battery, so you can't use the Infinity like a laptop. Regarding the latest model, specifically, ASUS Corporate Vice President Benson Lin doesn't think the laptop form factor is a feature that would help his company ship 1 million phones this year. In his defense, ASUS does need to keep the combined weight of the phone and tablet module to a minimum -- at least not much more than that of the iPad with Retina display for the sake of competitiveness.
At this point, this is only achievable by shaving off as much weight as possible on the PadFone Station, hence the lack of a docking socket and circuitry for a docking keyboard this time around. Of course, this isn't a flaw, per se, but the lesser package may struggle to convince folks who were sold on the original PadFone concept. On the other hand, the simpler and lighter package could help win more users, anyway. Compared to the 4G iPad, which weighs in at 662g, the PadFone Infinity's combined weight of 677g (145g plus 532g) is still very competitive, and it's not that far off from the PadFone 2's 649g. For those who do miss the laptop form factor from the original PadFone, there's always the Folder case or TranSleeve case, which lets you prop up the PadFone Station and then hook up the device with a Bluetooth keyboard. You can also connect a USB keyboard via an optional adapter.
The new PadFone Station comes with the same 5,000mAh battery (made by Sanyo) as its similar-looking predecessor, meaning it can, theoretically, charge up the docked phone twice in battery pack mode; or you can keep the phone juiced up -- either matching the module's battery level or prioritized, depending on your setting -- while using it as a tablet. Now, since this new PadFone Station comes with a more demanding 1,920 x 1,200 IPS panel (from Panasonic), the battery shouldn't last as long as it did with the previous 1,280 x 800 screen; but the quality upgrade is well worth the small sacrifice. Plus, there are mechanisms on the software side to optimize battery life.
As before, you'll also find a nice loudspeaker, a microphone and a micro-USB port on the PadFone Station, but they've all been relocated. The loudspeaker, powered by an 18mm driver, has effectively swapped places with the microphone, so that it's now behind your right hand and well away from the tablet's volume rocker and power button on the left. As for the micro-USB port, it's been moved from the bottom edge to the right side, which means you can finally plug a USB peripheral into the tablet while it's propped up by its case. The same old 1-megapixel front-facing camera (with Azureware's sensor) is at its usual spot -- in the middle of the screen bezel's top edge, but it's no match for its 2-megapixel counterpart on the phone.
Like the PadFone 2, the Infinity's PadFone Station uses a docking-retention system involving four serrated silicone rubber grips, which hold onto the two vertical sides of the phone. In a nutshell, this cunning design keeps the phone securely docked even when shaken upside down, while also allowing the user to pull the phone out with a gentle grip. This is best illustrated by the above graph (courtesy of ASUS), which shows how the required push and pull forces are carefully calibrated across different phases during docking. However, we couldn't help but notice a light rattle when we gently shook our docked Infinity module. Not that we've managed to shake the Infinity out of the tablet (seriously, we actually tried really hard), but we definitely never encountered such a nuisance with the PadFone 2.
We brought the offending mass-production devices to ASUS' office and tried our phone with another PadFone Station. The result? A lighter rattle this time, but finally we came across an engineering sample module that kept the phone very still, ironically enough. Upon close inspection, it appears that this sample's docking bay had a slightly thicker padding than our two previous modules. There's clearly a problem with the consistency of build quality, but if anything, the light rattle would only be slightly annoying to some, rather than having the potential to cause any damage.
Other than that one niggle, we had no problem holding the PadFone Station in either portrait or landscape. While the majority of the tablet module is 10.6mm thick (the thickest point being about 15 to 16mm thick over the docking bay), the tapered edges on the left, right and bottom sides give a nice fit in our hands. The matte, but smooth, rubbery finish certainly helps, too. The PadFone Station also comes in one of three colors to match the phone, but you're welcome to slip a pink handset into a gold tablet if that's how you swing.
The lack of heavy skinning helps keep the system running like butter.
We've always been fans of ASUS' approach to customizing Android. Which is to say, it mostly sticks to the stock OS. This is surely one of the reasons it often beats the competition to rolling out major updates, not to mention offering regular fixes. And of course, the lack of heavy skinning also helps keep the system running like butter. In the case of the PadFone Infinity, we've already received three OTA updates over the last two weeks (taking us to build 10.6.8.10 based on Android 4.1.2; not Android 4.2 as promised at launch), which is pretty typical of a freshly launched ASUS mobile device. Such a rapid rate is of course highly commended.
The fact that ASUS continues to use near-vanilla Android is by no means an indication that the company's been cutting corners. In fact, it's quite the opposite. First of all there's the classic ASUS Quick Settings feature that adds a row of customizable quick toggles (for auto-rotate screen, WiFi, WiFi hotspot, Bluetooth and more) and a screen brightness slider to the pull-down notification tray, and this is consistent across both phone mode and tablet mode. Given that you can disable ASUS Quick Settings, we're certain that you'll be able to switch to Android's native quick settings tray when the eventual 4.2 update comes along. Still, we're quite content with ASUS' implementation.
ASUS has also made subtle changes in a few other areas. For one, the "Pad only" tab in the tablet mode's app tray is still there, where users can filter out pad-only apps for quicker access. There's also a small drop-down menu in the app tray for sorting apps by name, frequency or download time. Not sure what took this so long (or why vanilla Android never had this in the first place), but we're glad it's here now.
Another stealthy tweak lies in the home button: when you long-press it, rather than showing just the Google Now button, the Infinity gives you two rows of shortcuts. The outer arc hosts up to eight customizable app shortcuts, meaning you can jump to any of these apps from anywhere at any time. The inner arc, meanwhile, gives you buttons for ASUS Echo (for voice command), Google Now, device lock, app tray and settings (for selecting the outer arc's shortcuts). We have mixed feelings about this one, as we've gotten used to flicking our finger from the home button to the lone Google Now shortcut on many other phones; so it'd be nice if there was a way to disable this feature. That said, maybe this will come in handy once you get used to it.
Moving to a higher level in the UI, ASUS has decided to throw in the ability to change the home screen scenarios. Yes, it's basically like "Scenes" in the older versions of HTC's Sense UI, but HTC has ditched it in Sense 5, with the reason being not many people actually use it. Perhaps ASUS' more intuitive implementation will popularize this feature once again: you toggle the scenario-selection mode by simply pinching the home screen. Then you can either edit your home screens or switch to another scenario from there. Out of the box, the Infinity has already set up a "Work" scenario filled with productivity widgets, as well as an "Entertainment" scenario featuring shortcuts for multimedia apps and a couple of social networking apps by ASUS. You can, of course, create your own scenario from scratch as well.
The killer feature of the PadFone series is obviously Dynamic Display, a fancy name given to the way the current app is kept alive when switching between phone mode and tablet mode. The good news is that not only did ASUS keep the switch time below two seconds, but the list of compatible apps out of the box has grown tremendously, including many of the 23 ASUS apps we'll talk about in just a moment. As before, essential apps like Calendar, Camera, Contacts, Gallery and Messaging can still seamlessly switch between the two interface modes. In other words, you can show off how a video clip keeps playing in the bigger screen once you've docked the phone, or how the calendar switches from phone mode to tablet mode, as opposed to just scaling up to fit the larger screen.
Annoyingly, flagship Google apps like Gmail, Google+, Maps, Hangouts and YouTube are grayed out on the Dynamic Display list, as they are still not compatible with one of the main selling points on the PadFone series. Those that do work well include Chrome, Drive, Play Music, Play Store, Search and Translate, but they require manual enabling in settings for some reason. As for the non-bundled or non-Google apps, your mileage may vary: we had almost no problem with our own Engadget app, nor Dropbox, Facebook, Foursquare, IMDb, MX Player or SoundHound. Still, we found glitches in Amazon Kindle, Evernote, Firefox and Twitter -- usually in the form of weird font sizes or displaced UI components.
Now, going back to the ASUS apps. If you've already played with ASUS' previous Android devices, then you should already be familiar with most of them. These include ASUS Studio for viewing photos (by location, face or tags); MyLibrary for e-books; AudioWizard for boosting the loudspeakers or headphones (the latter part is new, but not as well-tuned, suffering from volume fluctuation); MyBitCast (a note-taking app that supports audio recording); SuperNote; Watch Calendar (calendar displayed in the style of a clock); and WebStorage. The old Instant Dictionary widget is also here and can be toggled through the quick settings in the notification tray, after which you can hit the round floating widget to highlight any text for instant lookup.
Of the new bundled apps, the notable ones include ASUS' Splendid onscreen color tool, as seen on ASUS computers, as well as ASUS Echo, ASUS Story, Birthday Reminder and ASUS To-Do. We're particularly fond of ASUS Story (pictured above), which lets you create photo stories in neat collages -- great for presenting your family photos or just for killing time. ASUS Echo, on the other hand, failed to impress. While the company made a big deal out of this voice-command app at MWC, it sometimes wouldn't even respond to the scripted commands for making phone calls. Even if that worked, we were hoping for a natural conversation experience that we're used to with Apple's Siri, but Echo is nowhere near that level of sophistication.
ASUS has also come up with a couple of social networking-related apps: BuddyBuzz and PinPal. The former aggregates news from your various networks -- Facebook, Plurk, Renren (China's take on Facebook), Twitter and Sina Weibo -- and presents the feed in a magazine-like interface. PinPal, on the other hand, focuses on your selected friends' Facebook and Twitter feeds, and it displays their posts in a bland, but cleaner style for some creepy stalking. While we prefer BuddyBuzz to PinPal, both apps have crashed many times on us, with the former also suffering from poor photo rendering as well as struggling to grab images from Weibo, while the latter can get a bit laggy when it manages to stay running. Until ASUS sorts these apps out, we recommend staying away to minimize your agony.
On a brighter note, some of these ASUS apps also come in the form of floating widgets in tablet mode -- much like the ones you get on Samsung tablets. To toggle these, simply hit the arrow at the bottom-left corner of the screen, and then you'll be shown a selection of 10 resizable floating widgets: AudioWizard, Browser, BuddyBuzz, Calculator, Calendar, Video Player, Countdown, Stopwatch, Dictionary and Email. If that's not enough, you can also add some of the normal widgets to the list, but you won't be able to resize them. Our only issue with the default floating widgets is that they respond slowly when we resize them, but chances are this is something that ASUS can also fix via an update.
It's no surprise that we're seeing better results this time around.
As mentioned before, the PadFone Infinity shares the same 13MP image sensor as the PadFone 2, except this newer device comes with a brighter f/2.0 lens. Add in the fact that ASUS has had more time to optimize the sensor's firmware, and it's no surprise that we're seeing better results this time around. In our PadFone 2 review, we complained about the severe loss of detail in night shots due to the high noise-suppression rate, so we're happy to say this is less of an issue on the Infinity. (And for the record, the PadFone 2's also received a fix for the aforementioned issue since our review.)
In the comparison shots against the HTC One (shown below), you can see how the distant billboards maintain a fair amount of detail in the Infinity's photos, though the One still edges out with better color accuracy, presumably due to its larger pixels. As for HDR, we much prefer the results on the Infinity at night, but we did find ourselves too often relying on said feature, as the contrast of the images would otherwise be too strong (this can also be fixed in post by adjusting the gamma using a photo editor). Daytime performance is quite good in general, faithfully reproducing even the fluorescent range of colors. However, we regularly had to manually increase the exposure when trying to capture subjects under the bright sky.
Little has changed with the camera app since we reviewed the PadFone 2. With the volume keys facing upward in landscape mode, the app's intuitive layout gives you dedicated buttons for taking stills and recording video on the right (you can also capture full-resolution stills during filming). Meanwhile, the left column is occupied by various settings: modes, resolution, effects and exposure. The top-left button lets you toggle between still camera settings and video camera settings, without locking you down to either still mode or video mode -- a problem that many other camera apps suffer from.
While you can use either the virtual button or one of the two volume keys to trigger the camera, the Infinity also comes with a new voice-activated shutter that responds to "shoot," "cheese" or "one, two, three," and you can activate this mode in the settings menu at the bottom-left corner of the camera app. The only real caveat while taking photos or videos is that when using the Infinity in tablet mode, you need to make a mental note of the phone's actual orientation. Put simply: if you want to take a landscape photo or video (as you should), you need to hold the tablet in portrait mode.
Like most flagship phones these days, the Infinity's camera is listed with zero shutter lag, but we noticed that this is disabled out of the box. We soon found out why: once enabled, the virtual viewfinder started to stutter, presumably due to the extra resources taken up by the sensor and its ISP. Regardless, you can enable burst mode, which supports continuous shots at up to 8 fps -- up from 6 fps with the PadFone 2 -- for up to 100 shots in the full 13-megapixel resolution. This also works with all 10 filters offered by the camera app, with our favorite one being the "Dropper" that lets you remove certain colors in the live feed.
There are eight scenes available for the still camera: portrait, landscape, night, snow, sunset, party, backlight and vivid. These are usable in all of the camera modes, including the aforementioned HDR mode, portrait mode (formerly "beautification mode", for eye enlargement, cheek blushing, face slimming and removing skin shine), panorama mode and a new GIF animation mode. Making a GIF image is very much the same as shooting a 30-frame burst, with a choice of 0.8 megapixels, 0.3 megapixels or 0.1 megapixels in 4:3, or one megapixel in widescreen ratio. The files do get quite large very quickly so the lower resolutions are recommended.
The video camera mode is very much the same as before. On top of the usual set of resolution options, you can also pick one of the following high-frame-rate modes for slicker playback: 1080p locked at 30 fps, 720p varying between 20 fps and 60 fps, and 480p varying between 20 fps and 90 fps. Alas, the varying frame rate is to compensate for the shooting environment's brightness, so don't be alarmed if your nighttime clips come out just as choppy as those taken in the normal mode. While we're on the subject, ASUS has also added a slow-motion mode (muted) in either 720p or 480p, though there's no way to control how much you slow down, as there is on the Xiaomi Phone 2.
As on the PadFone 2, the video camera mode has the same set of filters as the still camera mode. Similarly, there's also a set of silly face effects that do funny things with one's face, eyes, mouth or nose, though these are limited to 480p, which should be adequate for a quick laugh. Going back to normal video mode, there's not much to complain about with the picture quality, but we did notice that the first second of audio always gets chopped off, followed by a sudden drop in noise at about three seconds into each clip -- presumably to do with the phone's active noise cancellation. Again, we're certain that both of these can be fixed via an update. Here are a couple of sample clips to keep you occupied for the time being: the first one a 1080p 23fps video, and the second one a 720p 50fps video.
Performance and Battery Life
With Qualcomm's Snapdragon 600 SoC and 2GB RAM turning up on almost every flagship Android device these days, there's no need for us to do a long presentation on how powerful this chip is in terms of number crunching and graphics rendering. Apart from the incompatibility issues we hit with certain apps over Dynamic Display, we've experienced virtually no lag in day-to-day operation. Additionally, heavy games like Need For Speed: Most Wanted and The Dark Knight Rises are simply stunning and slick thanks to the beefed-up Adreno 320 graphics chip. Even more amazingly, our Infinity never got too hot after completing a few races on NFS.
||Galaxy S 4 (Exynos 5 Octa)
|Vellamo 2 HTML5
|SunSpider 0.9.1 (ms)
GLBenchmark 2.5 Egypt HD C24Z16 Offscreen (fps)
|SunSpider: lower scores are better
Given that the HTC One and the PadFone Infinity share an almost identical set of specs, it's no surprise that the two devices also have very similar benchmark scores. But that's not quite the case with our 1.6GHz Exynos 5-powered Galaxy S 4 (SHV-E300S, to be exact), which appears to be ahead of everyone in terms of 3D graphics and memory performance. That said, while we have yet to determine this particular S 4's battery life, it's safe to say that the PadFone Infinity should easily beat it thanks to the extra juice in the PadFone Station.
As mentioned earlier, ASUS offers different charging policies to let you decide how to split the battery power between the phone and the tablet module. Here are the options: Intelligent mode for balancing the two devices' battery levels, Phone Preferred mode for maintaining a power supply to the phone and Power Pack mode for using the PadFone Station solely as a power pack (but you can hold the power key for two seconds to wake up tablet mode). These can be set in either the PadFone Assistant widget or in system settings.
To help further extend battery life, you can also toggle Smart Saving (either in Quick Settings or system settings) and choose one of several of modes. Ultra-saving mode disconnects the device from the network when it's suspended, whereas optimized mode toggles the appropriate screen brightness, network sleep time, CPU speed and number of active CPU cores in certain scenarios (like reading emails, reading e-books, browsing websites and watching videos). If you're feeling adventurous, you can tweak each of these individual settings as well under customized mode.
We could easily survive two days with both devices on one charge.
In our two rounds of battery tests, we set the phone / tablet combo to optimized battery mode, left it on a 4G LTE connection and set the screen brightness to medium, before letting it play a 720p video on a loop. Including the final hour when the phone was running on its own battery, we managed to get about 6.5 hours of continuous video. Funnily enough, when we repeated the same test with just the phone, we got about 5.75 hours of playback. But don't be put off by these figures, as our review unit was stuck at a location with a weak LTE signal (and we'll check again when we get hold of a different carrier's nano-SIM). Also, keep in mind that the batteries lasted far longer in everyday use; we could easily survive two days with both devices on one charge. For the record, too, the phone takes about 2.5 hours to be fully charged using the original power adapter, whereas the tablet module takes about four hours, so be sure to plug your devices in well before you head out the door.
The PadFone Infinity is without a doubt the best phone ASUS has ever made, and it's a worthwhile upgrade from the PadFone 2 even for the specs alone. Thanks to that brand-new industrial design on the phone itself, we're confident that it'll get more attention than its two predecessors did. Pretty much everyone we've shown the device to praised the new look. While we're less concerned about the problematic new apps since they can be updated, we hope ASUS somehow finds a way to dampen the rattle of the docked phone.
But the question remains: can this new package convince more consumers that owning this is better than carrying two separate devices? As nice as the PadFone is, this three-generation-old formula risks becoming stale if it doesn't break the mold. If ASUS wants to win over the non-believers, it'd have to come up with a solution that can let people use both the phone and the tablet module at the same time. That's right, dual-screen multitasking. The closest thing we have right now is NEC's Medias W, but it's more of an experimental product and won't be produced in high quantities. Perhaps wireless display from the phone to the tablet module is the way forward? Do surprise us, ASUS.