On full auto, the 5MP camera does its best work in sunny conditions. No surprise there. Color temperature is spot-on and the focal range is broad. I've also nothing to complain about when it comes to focus and shutter speeds, although manually tapping to focus on different areas of the viewfinder was sometimes required to get the correct exposure. As lighting conditions worsened, I was impressed by how the camera held up. I did notice that pictures tended to adopt the hue of artificial lighting, so the auto-white balance setting isn't as good as it could be. I'd say better an image look the same as it does through the human eye, however, than one that's been crudely adjusted. Low-light performance is better than I expected, too, with snaps coming out considerably lighter than you'd think they would.
Video performance at 720p is much the same, although audio quality isn't a highlight. The camera is my favorite thing about the Lumia 630, mainly because it's above acceptable considering the price point. I'm only talking about the normal camera modes, as well, so there's even more fun to be had with Nokia's extra Lenses, such as Cinemagraph, Blink and Refocus.
Performance and battery life

Like earlier, lower-end Lumias, the 630's spec sheet is no trump card, but at least it's working with the current generation of Qualcomm chips. That would be a 1.2GHz quad-core Snapdragon 400, to be exact, paired with a miserly 512MB of RAM and 8GB of internal storage. Finding enough space for all your apps and media is no trouble, as the handset's microSD slot supports cards of up to 128GB -- and remember that WP 8.1 now allows apps to be installed onto expandable storage. That Snapdragon 400 SoC is by far the stand-out spec from that selection, and I've seen it ace performance tests on several Android smartphones of late, such as the Moto G and UK-only EE Kestrel.
I find myself questioning its place inside the Lumia 630, though. One of the pros of Windows Phone as a platform is that it's not resource hungry, which has meant Nokia could produce phones like the Lumia 520 and 620 at such compelling price points without sacrificing much in the way of user experience. The Lumia 630, as you'd imagine, feels just as slick as either of those handsets do. Popping in and out of menus or core apps happens as fast as you'd ever need it to, but it's the lack of improvement in performance that stands out.
The difference in app-loading speeds on the 630, compared with older Lumias, is negligible. Only when you put them side by side to test the disparity will you notice the 630 is a millisecond quicker. Asphalt 8: Airborne is one of the most graphically intensive mobile games on any platform, but the problem is that it's scaled to be friendly to all Windows Phone hardware. On Android handsets with a quad-core Snapdragon 400, you can see how capable the chipset is by pumping up the graphics settings to max. You can't change such settings on the Windows Phone version, but even at a low visual standard, I experienced dropped frames and jittery music. I can't remember the last time I noticed a phone's temperature rising, other than when using the 630. Anything you would consider hardware-intensive, from gaming to streaming video, quickly drove the thermostat up to alarming levels.

Having been impressed with the same SoC on Android devices, I imagine it's a case of poor optimization. While the processor upgrade doesn't seem to have made much of an impact on performance, it's a burden on the 630's 1,830mAh battery. With fairly moderate use, I could barely get through half a day on a charge. If you want to do something a little more processor-intensive than checking your emails, be prepared to watch the charge melt away before your eyes. When I wasn't out or using the handset, it was permanently on charge. That's no way to live. Annoyingly, the battery indicator is misleading, too -- the icon will have you believe you have around three quarters left, but if you look in the notification tray, you'll find it hovering just above 50 percent.
Update: After posting this review, Microsoft/Nokia insisted I'd been given a non-final device, as evidenced by severe battery life issues I experienced. Testing a second handset has confirmed as much, and the 630 actually has above average battery life. Even with relatively frequent use, including browsing, taking pictures, sending email and streaming music, it's been good for a full day and half of the next. Using the battery saver feature only added to the longevity. I've also noticed the screen is slightly improved on the second unit, which you can read more about in the display section.
Internet Explorer is your window to the web, and it's not the fastest mobile browser. Regardless of your connection, sites can take a good few seconds to pull up (they load completely, rather than piecemeal). After they've loaded, the only other curiosity is some tiling, which can be caused by rapidly zooming in and out. For connections, you've got WiFi, Bluetooth, GPS and HSDPA 3G (21.1 Mbps max download speeds). WiFi connects quickly, but doesn't hold a consistently strong pairing, at least according to the signal icon. The speed and accuracy of GPS location is superb, and a nice companion to Windows Phone's excellent mapping options.
Audio quality is also worth a mention. Through headphones, the range is better than quite a few smartphones, but that's let down by kind of a vapid, clinical tone to the sound. Under the polycarbonate shell of the 630 sits an abnormally large loudspeaker that pumps through an abnormally small grille. Realistically, this is for making hands-free calls, not getting the party started. It's just strange that audio quality through this speaker is actually better with the case off. Reverberations inside the cover give a greater sense of bass, but really it's just distortion from the grille bottleneck.
The 4G Lumia 635

The Lumia 635 is almost identical to the 630, but with the key addition on an LTE radio. While the 630 didn't rise above what Nokia had already achieved with previous budget handsets, the 635 is a much more welcome addition to the range. The only other affordable, 4G device Nokia has to offer is the Lumia 625, launched last year. The handset had a number of flaws -- particularly its large, low-resolution display -- and only just crept into an acceptable price range. It was a missed opportunity after the highly regarded 620 had earned Nokia some cred, and the better-executed Lumia 635 is a great example of what the 625 should have been.
The Lumia 635 hardware differs from that of the 630 in a couple of ways. There's the LTE radio, of course, which has minimal impact on overall battery life compared to its 3G counterpart. With moderate to frequent use, the 635 runs out of gas a few hours earlier than the 630 does under the same conditions, but by this point you're well into day two anyway, so we're dealing with a relatively negligible margin. Otherwise, it's just the style of the polycarbonate back covers that distinguishes the two variants. The 630's have a matte effect, while the 635's have the glossier "dual-shot" style of shell we first saw on the 620, where transparent plastic is layered over a colored base to give the shell a visual depth. These give the phone a lot more character, though all matte and glossy covers can be used on both the 630 and 635, leaving plenty of options in hue and texture.

With LTE, the 635 is a much more attractive handset for US carriers to range than the 3G 630. Availability is still limited, but you can buy a 635 locked to AT&T for only $100 (off-contract), which appears to be by far the best value 4G handset it offers. It's the same story at T-Mobile, even though a device locked to that network is almost a third more expensive at $129 (from Microsoft's store; it's $168 direct from T-Mobile). I'd usually refer to the benchmark of affordable 4G phones at this point, the Moto G LTE, but it's in a different league at $219 (unlocked from Motorola; no carrier deals exist currently).
The situation is slightly different in the UK, mind you, where competition is fiercer. Both the Moto G LTE and Lumia 635 can be had for free across various carriers on the most basic 4G contacts. Unlocked, the cost of the Moto hovers just over £150, making the Lumia only slightly cheaper at £137. Pay-as-you-go price, however, favors the 635 more heavily and Phones 4u is currently asking for £110 and your choice of any network (note only Carphone Warehouse comes close to that at £130). The Moto G LTE, on the other hand, will set you back £150 (just shy of the unlocked price) unless you take Tesco Mobile's offer of £135.
The final call on which affordable phone is the best is really down to budget and preference. If you dig Windows Phone, especially after the recent 8.1 upgrade, then the 635 is a bargain at £110 on pay-as-you-go. The EE Kestrel is even more of a steal at £99 if Android's more your thing, though that does limit your carrier choice somewhat. Those happy to open their pockets a little wider might want to opt for the Moto G LTE instead, something I'd recommend for the higher-resolution display and better camera alone. The important thing is there's no wrong answer, and Nokia and Microsoft finally have the solid, low-cost 4G option the 625 struggled to be.
The competition

Normally this section would be about comparing the smartphone to what else is out there. This time, though, it's an exercise in proving why there is no need for the Lumia 630. Let's start with the price. We know the 630 and 635 are expected to cost under $200 in the US, with the single-SIM 630 said to be $159, assuming it'll even launch there -- the 635 will definitely have some presence on T-Mobile, possibly in July if everything plays out as planned.
I'm not sure where the price of the 630 was lost in translation, but Nokia's UK press release that pre-empted the device's launch said it would be available for £90 unlocked. In reality, the cheapest you can get it for is £99 on a locked, pay-as-you-go basis. SIM-free, that rises to £109 from one retailer, and Microsoft's even selling the handset through its online store for an insulting £129. Last year's Lumia 620 may have a lesser processor, but it's a better phone in every other respect. Also, given its age, it's comparable on price at £100 on pay-as-you-go or £110 unlocked. Even the Lumia 520 is a better option at £60 on pay-as-you-go or £85 unlocked.

If you're dead-set on Windows Phone, the Lumia 630 is not the right decision. That's if you would even consider any of the handsets I've mentioned over affordable Android offerings from the likes of Motorola. The amazing Moto G is £110 on pay-as-you-go or £130 unlocked, whereas the Moto E is even cheaper at £79 on pay-as-you-go or £89 unlocked. Better handsets, better mobile platform -- better forget about the Lumia 630.
The Lumia 635 will be more relevant when it launches, thanks to that LTE radio, and the only other affordable Lumia with 4G is the depressing 625. I dread to think what a 4G radio will do to the already-poor battery life, and the 635 will still have to face off against the LTE version of the Moto G (not yet released). Unless Microsoft intends to give the 635 away for free, I don't see my opinion being any different with the addition of LTE.
Wrap-up

I can't help but feel that the Lumia 630 was thrown together to be a Windows Phone 8.1 demo device, and then someone decided it was suitable for a retail release. I couldn't disagree more. Forget that Microsoft still has come catching up to do before its mobile OS is considered on par with others; the hardware itself is lacking. The display is poor, and even the glass covering it is missing whatever coating most other handsets have to repel fingertip grime. There's no noticeable performance improvement over previous budget Lumia devices despite a newer, more capable chipset, and battery life is nothing short of atrocious. It's even missing basics like a front-facing camera or HSPA+ 3G radio.
To its credit, the 5-megapixel camera is better than you might suspect, and it has the Lumia line's signature fun, colorful stylings. If the handset cost less, I'd probably feel differently about its shortcomings, but the truth is there are better and comparable phones available for less. I have no choice but to issue a stern warning to avoid it, as there are several attractive and more affordable alternatives.
Update: After spending time with a second review unit, my opinion of the Lumia 630 has improved. Battery life is actually one of the handset's strong points, and the display installation is much tighter on the second review unit. Combined with a respectable 5-megapixel camera, it's not a bad package. That said, the 630 is still missing basic components like a front-facing camera and HSPA+ 3G radio, and there are plenty of good alternatives at lower or comparable prices.
Daniel Orren and Edgar Alvarez contributed to this review.