Shortly after Nokia announced its latest mid-level Windows Phone 8 device, the Lumia 820, it announced that there would be carrier-specific variations of the handset. While the hardware specs and features like its interchangeable shells would remain the same across the board, AT&T, Verizon, and T-Mobile would all get differently-designed versions of the phone.

The Lumia 810 is T-Mobile's offering, and while it offers quite possibly the most attractive design out of all three versions, the fact that it's tied to such a weak network is easily its greatest flaw, making it hard to justify its purchase unless you're already on T-Mobile. Few people are willing to switch to a new (and inferior) carrier just for the sake of having a specific phone, and this Windows Phone 8 smartphone is no exception. That being said, almost everything else about the Lumia 810 impresses, likely making users wish for a perfect world in which it's offered on a better network.

Build and Design

Though I may be of the opinion that the Lumia 810 is the most attractive carrier-exclusive variant of the Lumia 820, right off the bat, I was a little disappointed by the design of the Lumia 810. It wasn't, however, because I thought it was ugly, but rather because it came so close to perfection, only to miss the mark by a hair.

For the Lumia 810, Nokia adopted a sleek but simple design, with subtly rounded corners complimented by a flat back and edges. As far as its shape is concerned, it's like every sexy Windows Phone prototype or conceptual art you've seen (that Microsoft Surface smartphone concept art comes to mind), all clean-cut and stylish.

These were the very thoughts I had about the build of the Lumia 810 the moment I saw press images of it, but once I saw it in person and held it in my hand, I realized that its dimensions are ever so slightly off; they're just enough to make it look and feel a little chunky. It's just a tad too wide, a smidgen too long, a bit too thick.

The length is probably the most apparent, what with the obvious wasted space beneath the capacitive navigation buttons below the screen. The fact that it's a little too wide isn't as obvious until you attempt to reach something on the opposite side of the screen from your thumb and realize that it's an uncomfortable stretch.

As for the phone's thickness, Nokia tried to be a little deceptive about it; the front of the Lumia 810 creates a right angle where it meets with the flat sides, which appears to give the handset an acceptably thin profile if viewed at an angle (say, in flattering press shots). But instead of another sharp edge where the side meets the back, it's an obtuse angle because the phone actually continues to swell outwards, puffing up the shape and making the phone a little too thick. The shots of the top and bottom of the handset featured here gives a good idea of how the Lumia 810 is shaped.

So yes, in a way, the build is a bit of a letdown, because all of the dimensions add up to create a phone with a footprint that's slightly oversized and disappointingly close to being a fantastic design.

While I'm complaining, I'll also mention that the buttons, as well as the Carl Zeiss frame around the rear-facing camera, are covered in an odd "metallic" black plastic. When clean, it looks sharp and works well with the all-black coloring of the handset, but it's remarkably prone to smudges and fingerprints. The only way it ever looks decent is if you wipe down the surfaces and then just never touch them, which has proven to be especially difficult with the buttons.

But the Lumia 810 does have a nice matte finish on the back, which I always love. And yes, as this is one of the carrier-specific variants of the Nokia Lumia 820, the back plating is removable to allow for microSD, SIM card, and battery access. Different shells can also be purchased and swapped in to allow for a different color (cyan) or wireless charging capabilities.

Display

For an 800 x 480 resolution display, the AMOLED screen of the Lumia 810 still looks more than decent thanks to Nokia's ClearBlack display technology, which, as the name suggests, creates deeper blacks to enhance the contrast and cut down reflectivity. And on its highest setting, the screen can be shockingly bright, to boot.

As such, the display looks good even outdoors, and the colored tiles of the Windows Phone home screen look especially crisp against the black background (assuming your background is set to black and not white). Despite the lower resolution, the display never appears grainy or pixelated, so I imagine only the real purists will be unsatisfied with the quality of the screen.

Other Buttons and Ports

Unlike most of the Windows Phones we've reviewed in the past, the Lumia 810 loads up all three physical buttons -- the volume rocker, the power/standby switch, and the camera button -- on the right side of the device. Initially, I thought it would be tough to get used to having the standby button on the side of the phone instead of the top, where it's usually located. But I found that it was actually more natural to reach and press it with my thumb or middle finger while holding the handset, rather than stretching up with my index finger to hit a button on the top.

Other than that, however, there aren't really any other surprises with the design of the Lumia 810. The headphone jack is placed on the top edge, while the micro-USB/charging port is on the bottom edge. It is worth noting that while there are also two speaker grills on the bottom, suggesting stereo speakers, removing the phone shell reveals that there is, in fact, only one speaker behind the grills.

As for the cameras, the rear-facing shooter and its flash are the only things adorning the back side, while the front-facing camera is located just to the left of the phone's earpiece.

Performance

Despite the fact that the Nokia Lumia 810 is meant to be a mid-tier smartphone -- its big brother being the AT&T-exclusive Lumia 920 -- it performs extremely well, at least on the hardware front. It's actually powered by the same 1.5 GHz, dual-core Qualcomm S4 processor as the top-tier HTC 8X, giving it comparable performance even though it's the more affordable option; after online-only discounts, the Lumia 810 is free from T-Mobile with a two-year contract, while the 8X is still $200.

In fact, according to benchmarks provided by WP Bench, the Lumia 810 technically outstrips the HTC 8X as far as hard numbers are concerned. Over a run of five tests, the Lumia 810 averaged 240 marks and a high of 250, higher than the 8X's score of 229.29. That being said, one probably wouldn't be able to tell the difference between the performances of the two handsets in practice, which are basically the same; the efficiency of Windows Phone 8 helps keep everything zippy, while even the more intensive apps ran without any lag or slowdown.

At 8 GB, the phone's storage isn't exactly plentiful, but thankfully the Lumia 810 has expandable memory via microSD, which is always a welcome feature. To access the card slot, users just need to pry off the back shell, easy as pie.

Not everything is perfect with the Lumia 810 though, because far and away the phone's biggest detractor is the network to which it's connected. T-Mobile is just awful; not just in terms of its speeds (HSPA+, in my experience, does not perform as well as LTE), but in terms of its coverage. I don't understand how I can live in a relatively significant city like Boston and yet always be struggling to find a signal.

More often than not, the Lumia 810 switches down to a 2G or a 1X network; on the rare occasion that I have a "4G" signal, it's never more than one or two bars. In my entire time with the unit -- during which I used it not only in Boston, but also Philadelphia and Connecticut -- I never saw it with a full "4G" signal. It's a real shame, because the Lumia 810 is otherwise a quality device...but unfortunately, the data connection is kind of an important factor in its performance. After all, it's the very thing that allows so many of its (and Windows Phone 8's) attractive features to actually work.

Software

There's no shortage of preloaded software from Nokia on the Lumia 810, with almost equal amounts of hits and misses. Since the Lumia 810 runs Windows Phone 8, there's a little more room for some game-changing software -- or at least software that helps set the phone apart from other devices for reasons other than hardware.

There's definitely a fair share of throwaway apps just cluttering up the phone right out of the box, including 411 & More, App Highlights, Bonus Apps (apps exclusive to T-Mobile data plan subscribers, which would be good in theory, but they're all garbage), CallerTunes (so you can pay extra to have people calling you have to suffer through whatever song of choice you pick), ESPN, Slacker Radio (some users may appreciate this, but I don't know anyone who uses it), T-Mobile TV, and Zynga Games (just links to app downloads, nothing I hate more).

There are a couple of logistical things that may or may  not be handy to you, depending on your situation, like a My Account app for information about your T-Mobile subscription, or the Transfer My Data app, which allows you to do exactly that with your previous phone, as long as it has Bluetooth.

The Nokia-branded content is where it starts to get more interesting. Yes, there are a couple of redundant apps, like Nokia Drive, Nokia Maps, and Nokia Music, which all more or less perform functions that can be accomplished with baked-in apps, like Bing Maps or Xbox Music -- though I would venture to say that Nokia Music is probably the most different, what with its gig finder and free mix radio. There's also Nokia Transit, which has proven to be a surprisingly capable app for those of us who live in a city. All of the other transit apps that I've tried in the past couldn't seem to pull up scheduled times for the train line that's closest to where I live, but Nokia Transit could and has subsequently proven to be quite useful to me.

It's when you get to Nokia's "lenses" that things get really interesting, though. Windows Phone 8 allows for different "lenses" to be used within its camera app, which basically lets users utilize the camera to perform unique or specialized functions.

For example, there's the City Lens, which is essentially an augmented reality app, using the camera to display your surroundings on the screen while tagging nearby points of interest in whatever direction you're facing (while also indicating, by the size of the icon, how far away they are from your current position). There is also the Panorama lens, which is pretty self-explanatory, as well as the Smart Shoot lens, which takes a series of shots when the shutter button is pressed so you can pick and choose elements from each of them (e.g. different faces) and combine them into one image for the perfect shot.

After you're done taking your photos, you can also edit them in the Creative Studio, which allows you to select different filters and adjust color balance, brightness, clarity, and vibrance.

But I was a particularly big fan of the Cinemagraph lens, which was essentially a GIF maker on steroids. Users can capture moving pictures -- not videos -- and then tinker with them after the fact: elements in the picture that are moving are tagged by the software, and users can decide whether or not to animate them. So for instance, after taking a picture of two people standing next to each other and waving their arms, I can use the Cinemagraph lens to highlight one of the people and freeze them mid-action while keeping the other person in motion. The software isn't just neat and fun to mess around with, it's actually quite impressive.

That being said, I can't really think of any practical or particularly useful applications for the Cinemagraph lens, other than to use it to just have fun. But perhaps that's the point of it.

Battery Life

The battery life of the Lumia 810 is great, especially considering that it's a 4G handset (well, T-Mobile 4G, which is actually HSPA+). Nevertheless, it provided better battery life than the last 4G Windows Phone 8 handset that I reviewed, the HTC 8X, and this is a phone that I usually leave on the maximum brightness setting because the screen just looks so darn good.

Since Windows Phone 8 has push notifications for many of its supported apps now, I tend to keep most of those on in addition to my email push, despite the fact that it's not great for the battery. Nevertheless, I was still able to get just shy of three days out of a single charge (though I did make the effort to keep Wi-Fi and location services off when I wasn't using them).

And while my usage was generally light -- reading emails, short sessions of web browsing -- there was the occasional heavy lifting thrown in there in the form of streaming videos or goofing around at length with Nokia's different camera "lenses". I really couldn't get enough of the Cinemagraph when I first tried it.

To give an idea of its capacity at a full charge, the settings menu indicated that the Lumia 810 had 6 days and 16 hours to spare the moment I unplugged it from a fresh charge. Not bad at all, though that number does, of course, refer to the remaining battery life if the phone were to be left in standby the whole time.

Camera

Unfortunately, the same problems that plagued the Carl Zeiss optics on the last generation of Lumias appear to still be present in the Lumia 810; namely, the issues with the white balance. Whites tend to gravitate to hot and cold tones very easily, depending on whether reds or blues are also in the picture.

Grain can also be seen in low-light shots, and similar conditions tend to disrupt the sharpness of the images at times, too. I found myself wishing that the Lumia 810, like the Lumia 920, was the beneficiary of Nokia's PureView imaging technology, as it could really use it to help take brighter shots.

However, when in suitable lighting, like the outdoors or well-lit rooms, the Lumia 810 could produce good quality shots with admirable sharpness. But in all, the 8-megapixel camera of the Lumia 810 is not the highlight of the handset, even if Nokia's proprietary photo software does make it a blast to use. It may be fun to use the camera to mess around with the "lenses", but don't expect the quality to blow you away.

Some will also be upset to hear that certain settings, like resolution or saturation levels, can't be tinkered with. The camera isn't devoid of any options, though, since you can toy with some of the other settings like ISO or exposure value.

Conclusion

The Nokia Lumia 810 is a fantastic mid-tier phone that is unfortunately dragged down by the performance of its carrier. While it's true that the same hardware is available on different networks (the Lumia 822 on Verizon and the Lumia 820 on AT&T), the simple but attractive design of the Lumia 810 is exclusive to the carrier, which is sure to disappoint many.

For an 800 x 480 display, the screen of the Lumia 810 truly shines (see what I did there?), the battery life is great, and the performance is surprisingly heavy-hitting for a handset that isn't even considered to be top-of-the-line. It's a shame that such a pretty -- but not quite perfectly designed -- phone is only available on such a poor-quality network, as it's just not worth suffering through the weak signals and spotty coverage.

If it's the affordable price and respectable action under the hood that attracts you to the Lumia 810, suck it up and go with one of the less attractive but better connected variants from either Verizon or AT&T.