Hardware
LG provided us with three Optimus G review units: an unlocked white handset with the 13-megapixel camera for Korea's Olleh LTE network, Sprint's almost identical black version and AT&T's bespoke model with the 8-megapixel shooter. Unlike Samsung's curved, pebble-like, "inspired by nature" theme, the Optimus G inherits LG's chiseled, angular, slab-like design language. The details are more subtle than with the Optimus 4X HD -- it's more of a simple and elegant tribute to past Chocolate and Prada phones. While Sprint's version shares the same appearance and dimensions as the Korean model (the reference, if you will), AT&T's handset is 2.8mm (0.11 inches) wider and 1mm (0.04 inches) shorter. Thickness is uniform at 8.45mm (0.33 inches) and weight varies between 145g (5.11oz) and 147g (5.19oz). Regardless of which Optimus G you handle, build quality is superb -- it's like holding on to a solid block of technology. AT&T's phone feels slightly too wide, but the other two are extremely comfortable in hand, thanks to subtly curved edges where the sides meet the back.
Regardless of which Optimus G you handle, build quality is superb -- it's like holding on to a solid block of technology.
In front, all three devices feature a beautiful 4.7-inch True HD IPS PLUS panel fitted under an edge-to-edge sheet of Gorilla Glass 2. The earpiece is flanked by sensors on the left and a 1.3-megapixel camera on the right. The Sprint and Korean versions also include an RGB notification light next to the earpiece (it's been relocated to the power / lock key on AT&T's model). You'll find three capacitive buttons below the screen (Back, Home and Menu) which are only visible when backlit. Interestingly, the bezel surrounding the display is black even on the white Korean model. There's no branding in front other than LG's silver logo up top and centered. Around the back, the Optimus G is covered by another sheet of what appears to be glass incorporating a pattern that's only visible at certain angles. This glossy finish, which LG calls "Crystal Reflection", is a veritable fingerprint magnet, especially on the black versions (Sprint and AT&T). It's interrupted only by the camera lens above the single LED flash in the top-left and a vertical slit hiding the mono speaker in the bottom-right. LG's silver logo returns along with carrier branding, except on Sprint's unit which is pleasantly free of network labels. There's no way to remove the back cover -- the Optimus G's sealed 2,100mAh Li-polymer battery is rated for 800 charge cycles (vs. the usual 400-600).

The most obvious difference between the three handsets is also our biggest design gripe. The Optimus G is available with either a choice of 8-megapixel or 13-megapixel shooters. Sprint follows the same recipe as the Korean model with the 13 MP camera sensor mounted in a protruding square pod and the LED flash embedded in the back. On AT&T's version, it's the reverse: the 8 MP module is located under the glass surface and the LED flash is recessed in its own divot. This inconsistency is annoying -- it makes AT&T's phone less visually appealing than the other two. We understand that the eight and 13-megapixel modules have different thicknesses, but LG could have used a similar square pod to house both cameras and simplified its assembly process while maintaining a cohesive design across models.
This inconsistency is annoying -- it makes AT&T's phone less visually appealing than the other two.
Each device sports identical controls and ports: a standard 3.5mm headphone jack and secondary microphone on top; the power / lock key on the right; a micro-USB / MHL connector, primary microphone and two screws at the bottom; and the volume rocker on the left. While Sprint's Optimus G is devoid of any extra openings, the Korean version includes a micro-SIM tray on the left side below the volume rocker and AT&T's model puts a flap in the same location covering both micro-SIM and microSD card slots. Our Korean unit also rocks a retractable T-DMB antenna in the top-left corner for that extra bit of street cred. Beyond the wider body and lower resolution camera, AT&T's handset deviates further with a completely different edge design. Where the Sprint and Korean versions have mostly flat sides with two handsome silver rings -- one along the edge of the front glass and the other a quarter of the way down the side -- AT&T's model features curved edges with a dark chrome finish on the left and right along with textured flat sides at the top and bottom. As mentioned above, the notification light on AT&T's Optimus G is located around the power / lock key (instead of living next to the earpiece in front).

By now you're probably wondering how that 4.7-inch True HD IPS PLUS panel stacks up to the competition. LG's Zerogap Touch technology puts the capacitive layer right inside the non-PenTile, 1,280 x 768-pixel screen for an ultra-thin design. It's definitely a top-notch display -- bright and crisp, with deep blacks and rich colors. Still, it falls short of HTC's gorgeous Super LCD 2 panel on the One X, which offers better viewing angles and remains the best screen on any phone we've ever used. Our Korean unit also suffers from a yellow discoloration at the bottom of the display -- it's mostly noticeable with a white background and we've alerted LG to the issue, which is likely the result of an early batch of defective panels. The Sprint and AT&T devices are flawless.
It's definitely a top-notch display -- bright and crisp, with deep blacks and rich colors.
Under the hood is where the Optimus G really shines. Reading the specs will put a smile on the face of even the most jaded tech journalist. It's the first handset built around Qualcomm's Fusion 3 chipset, which pairs a 1.5GHz quad-core Snapdragon S4 Pro SoC (APQ8064) with a 2G / 3G / LTE radio (MDM9615). Beyond the quad-core Krait CPU and Adreno 320 GPU, you'll find 2GB of DDR RAM and 32GB of built-in flash storage on board (reduced to 16GB on AT&T's unit, which also supports microSD and ships with a 16GB card). In terms of radios, the Korean version is quad-band GSM / GPRS (no EDGE), dual-band UMTS / HSPA+ (2100 / 900MHz) and LTE capable (Band 3, possibly 1 and 5). The Sprint model works on the carrier's CDMA and LTE technology in the US but should be able to roam on GSM / GPRS / EDGE (quadband) and UMTS / HSPA+ (dual-band 2100 / 900MHz) networks abroad. AT&T's phone supports quad-band GSM / GPRS / EDGE, tri-band UMTS / HSPA+ (2100 / 1900 / 850MHz) and LTE (Bands 4 and 17). Other specs include 802.11a/b/g/n, Bluetooth 4.0 + LE, A-GPS, NFC and a bevy of sensors (ambient light, proximity, magnetometer, accelerometer and orientation).
Performance and battery life
Let's make one thing perfectly clear: the Optimus G is a performance beast.
Let's make one thing perfectly clear: the Optimus G is a performance beast. Subjectively, it never skips a beat -- everything is snappy and fluid, with no lag or delays. Despite launching with Ice Cream Sandwich (Android 4.0.4, to be exact), it feels quicker than our Galaxy Nexus and on par with our Galaxy Note II, both running Jelly Bean. This is a testament to LG's UI optimizations, Qualcomm's engineering chops or both. In our benchmarks, the Optimus G slots right between our reigning champions -- the global Galaxy S III (ICS) and the Galaxy Note II (Jelly Bean) -- for most tests, while handily beating both with the best Quadrant score we've ever recorded for a handset (7,628) and barely lagging behind in AnTuTu (11,284). The results are similar across all three versions, with the Sprint model falling a smidgen behind the other two. It will be interesting to see how much these numbers improve once the Optimus G is updated to Android 4.1.
Update: We've added results for Vellamo 2 HTML5 and GLBenchmark 2.5 Egypt HD C24Z16 Offscreen.
We didn't have any issues with overall radio performance but calls sounded a little flat in our tests. AT&T's handset was the clearest, followed closely by Sprint's, with the Korean Optimus G (likely not optimized for US networks) trailing behind. The built-in speaker is somewhat tinny but loud enough. We didn't have much time to compare music playback with other phones, but audio quality with various headphones and earbuds was up to our higher-than-average standards. It's worth mentioning that LG's bundled music and video players feature Dolby Mobile, if you're into audio enhancement. Speed tests on AT&T's LTE network in San Francisco yielded about 12 Mbps down and 10 Mbps up (on average) with four out of five bars of signal. Until Sprint deploys LTE in the Bay Area we're stuck doing speed tests on CDMA, which means peaks of 2.3 Mbps down and 1 Mbps up with full signal. Our Korean unit only supports GPRS data here in the US, but we saw some impressive numbers with a prototype Optimus G on Korea's U+ LTE network while in Seoul.

Battery life on Qualcomm's dual-core Snapdragon S4 devices is usually fantastic, and we're happy to report this trend continues with the quad-core Snapdragon S4 Pro-equipped Optimus G. While all three versions have the same sealed 2,100mAh Li-polymer battery, we focused our attention on AT&T's model since it's the only one with an active LTE connection. Our standard battery rundown test involves setting the brightness and volume to half, using 4G in a 75 percent or better signal area, enabling GPS and WiFi (not connected) and disabling Bluetooth while looping a video from a full charge until the battery is drained. AT&T's Optimus G ran for eight hours and 43 minutes; Sprint's lasted seven hours and 53 minutes on 3G (LTE off); and our Korean phone kept going for eight hours and 40 minutes on 2G (LTE and HSPA+ disabled). In our moderate battery usage test, which consists of using a handset lightly from a full charge until it shuts down -- emailing, texting, checking social networks, making a few brief calls, taking some pictures, etc. -- all three review units went on for almost 20 hours. As such, we're pretty sure most people will have no problems using the Optimus G for an entire day. Heavy users can use "Eco Mode," a setting which extends battery life by dynamically switching between quad- and dual-core operation.
Camera
This is the story of promising shooters held back by a frustrating user experience.
This is really a tale of two different cameras with identical functionality -- the story of promising shooters held back by a frustrating user experience. Both the Sprint and Korean versions of the Optimus G use a 13-megapixel, 1/3.2-inch BSI sensor with 1.1µm pixels and a five-element, f/2.4 autofocus lens. AT&T's model sports an 8-megapixel BSI sensor with identical 1.1µm pixels, but it's unclear if the autofocus lens is the same (the 13 MP module captures a wider field of view). Both cameras are capable of recording video at 1080p and are complemented by a single LED flash. The user interface is similar on all three phones -- it's intuitive, customizable and offers a full range of settings. You'll find HDR, panorama and burst modes, plus features like "Time Catch Shot" (which buffers pictures in the background and stores five images centered around the time when you press the shutter button) and "Cheese Shutter" (which takes a shot when you say the word "cheese" or "whiskey").