In bright, consistent light, the M9 fires off detailed photos with nicely reproduced colors -- they can be a little washed out compared to the M8, though, and the cooler screen on the M9 doesn't help them look any better. Here's the rub: You'd expect this thing to be uniformly better than the UltraPixel shooter HTC's been pushing, but that's just not always the case. I'm not just talking about low-light situations where the UltraPixel camera truly shines, either. Sometimes the M9 comes through with crisper details; other times the M8 seems to do a better job. Sometimes the M9 has richer, more accurately exposed colors; sometimes it doesn't. You get where I'm going with this. It's such a mixed bag that I'm honestly surprised HTC gave in to the simplicity of advertising a camera based on its megapixel count at all. When the company dropped the news, I think we were all hoping the company's megapixel gamble would pay off in spades. Well, not so much. At least the UltraPixel selfie camera still works the way you'd expect. The lens is wide enough to capture most of your crew come Groufie time and, as usual, it excels in darker climes like bars and clubs (though you might come out looking a little pink for your liking).
On the plus side, HTC's Camera app is still one of the more in-depth we've seen ship on a smartphone, and it's easy enough to dismiss gritty technical bits like exposure control, ISO and white balance if you'd rather not bother. Oh, a quick heads-up to all those serious mobile photographers -- the M9 technically supports shooting RAW photos, but good luck getting that to work without a little dedicated developer support. Swiping to the left and right still lets you hop among Panorama, Selfie and standard Photo modes, and they're actually labeled this time too! It's all about the little things sometimes. Delve deep enough into the settings and you'll discover that HTC has finally put together a phone that can shoot video in 4K, though it'll only record 6 minutes of super high-def footage in a go. Sadly, most of my test recordings suffered from the same washed-out look that the M9's photos had trouble with during most of my weeks testing.
Speaking of the little things, HTC's full suite of image-editing tricks are back too, from mainstays like red-eye removal to body-horror playthings like Face Contour (seriously, run it on the same photo a few times and tell me you're not terrified). Feeling really festive? You can festoon your pictures with floating particles, be they snowflakes or cherry blossoms or shapes of your own choosing. I have no earthly idea why anyone would need this, but it's cute, so someone somewhere will surely have a blast with it. Too bad you can't save the resulting tableau as a GIF; it'll wind up being saved as a static JPEG or a video file. You'll have an easier time indulging your artsy side with the editor's new double exposure and Prismatic features, too. The former does pretty much what the name says (with occasionally freaky results like the shot above), but the latter takes a cue from apps like Fragment by letting you stick trippy polygons and line art on top of your photos. Trust me, it's cooler than it sounds.
Performance and battery life
HTC might not have been the first to out a Snapdragon 810-powered phone, but make no mistake: There's some seriously powerful silicon thrumming away inside the M9's metal frame. The surest sign of a strong performer is its ability to make you stop thinking about its performance altogether, and that's almost completely the case here. I've spent the better part of two weeks basically treating this thing like crap -- furiously firing up and cycling through apps, wiling away hours crashing into walls in Asphalt 8, watching high-res videos until I was bored stupid -- and I haven't yet found a scenario where the M9's combination of lightweight software and speedy hardware let me down.
Now about that elephant in the room. Yes, the M9 can get almost uncomfortably warm if you make it a point to push it hard -- I noticed it mostly during my repeated benchmark testing, which most average users will never, ever have to worry about. The M9's all-metal chassis still gets warm during more normal hardware-intensive tasks like bashing zombies in the face in Dead Trigger 2, but considerably less so than during benchmarks and never to the point where I was worried about hurting myself. By now, it's more than clear that the 810 isn't a particularly cool customer, and HTC gets some props for trying to mitigate the issue before the M9's official launch. That said, the company's approach to thermal throttling seems to have had an effect on the numbers the phone put up -- the One M9 and the G Flex2 were just about neck and neck throughout the whole process, save for a few tests where the M9 scored consistently lower.
You won't be left wanting for horsepower, but the 2,840mAh battery was more of a mixed bag. In the standard Engadget rundown test (with a video set to loop endlessly while the screen's set to 50 percent brightness), the M9 stuck around for eight hours and 19 minutes -- a decent increase over the original One M7, but far short of the 11-plus hours we squeezed out of the M8 last year and the 10-plus hours the G Flex2 put up. That seems abnormally low, especially considering that the M9 did just fine when it came to average daily use: It regularly hung around for 13 to 14 hours of continuous work use (including a few spells as a mobile hotspot during press events) without batting an eye. Using the thing judiciously could obviously pump up those numbers even more, as would firing up its Extreme Power Saving mode (though you'll lose access to all but the most crucial apps as a result).
I've been spending all this time with the international version of the One M9, and by the time you read this it'll have started trickling onto store shelves in a few far-flung markets. All four major US wireless carriers have pledged to carry it (no word on price yet, but the usual $650 sans contract/$200 with seems likely), so it won't be long before M9s will be all over the place. What else should you be looking at? We're starting to see the first batch of Samsung Galaxy S6 and S6 edge reviews make the rounds, and while we haven't spent more than a half-hour with the things to date, there's no denying that they're going to be two of the M9's fiercest Android competitors this year. We're looking forward to seeing how the Snapdragon 810 in the M9 stacks up to Samsung's homespun silicon, but the M9 already seems to have a leg up on the S6 when it comes to eye candy. The S6 edge is a completely different story -- I still maintain it's the best-looking phone Samsung has ever made -- but you're going to pay a hefty premium for a phone that's functionally identical to the S6.
If you need a high-powered competitor right now, there's always the G Flex2. LG beat HTC to the silicon-studded punch by bringing the Snapdragon 810-powered device to Sprint earlier this month (it'll hit AT&T soon, too) and it's strikingly pretty to boot. You'll miss out on Sense's occasional thoughtfulness and a rock-sturdy body, but LG's light touch with Android 5.0 and the sheer "wow" factor of a curvy phone just might be worth it for you. HTC's older One M8 is still no slouch either, and the punchier display, plus some slightly louder BoomSound speakers, might make it a contender for another year if you're persnickety about your media and don't absolutely need the latest and greatest.
It might sound maudlin, but I really wanted to love the One M9 as much as I did the One M7. This seemed like the year HTC would nail it again. They came close! I'm still surprised that it's Sense that I'm most impressed with. BlinkFeed is a first-rate time sink, and theming is a lovely, awfully personal way to kill a few minutes and make your M9 really feel like yours. Sure, the app suggestions are so bad they're almost great for a laugh, but I can ditch them whenever I feel like it. Alas, the M9 is let down by a camera that isn't as good as it should be, strangely tuned BoomSound speakers and the occasional questionable design decision. And yet, despite those quirks, the M9 is still a very, very good phone. It's an utter powerhouse even with thermal throttling in the mix and the now-traditional One aesthetic is as attractive as it's ever been (strange metallic edge aside). That doesn't change the fact that it's still the biggest question mark of the One trio to date, and now I -- along with others, surely -- are left wondering where HTC goes next.