Picked up a Verizon M8 on launch day as a replacement for my Galaxy S3. I had to give up my unlimited data for it, but it was bound to happen eventually and I was getting a little tired of paying off-contract price for everything. A few random thoughts:
1) The build quality is out of this world. Aside from the iPhone 4 (which I prefer, build-wise, to the tall, cartoonishly light iPhone 5), I don't think I have ever been so floored by the design of a phone before. The word "luxurious" sounds pretentious to me, but it's definitely fitting. It's elegant and executive, like a really nice watch. Much more comfortable having this on my desk at work than a white Galaxy phone, for example.
2) I'm really liking Sense 6.0. It's my first experience with Sense since the original Droid Incredible. I hate Touchwiz, and have installed stock-ish Android (CM) on every Android phone that I have used in recent years, but I find Sense 6.0 clean, simple, and unintrusive enough (yay for the ability to at least hide the Verizon bloat) that I'll probably end up keeping it.
3) Sound is fantastic. I have no basis of comparison against the previous M7, but music sounds incredible through decent headphones (yay also for pack-in headphones), and the front speakers are loud enough for bedroom television, movie, or YouTube viewing, or even for listening to podcasts while driving.
4) Display is top-notch. Again, no basis for comparison with the M7, but even as an unapologetic AMOLED lover, I'm kind of smitten with the Super LCD panel. Prefer my aspect ratios to skew a little less tall and a little more wide, and capacitive buttons beside the HTC logo would have freed up some additional real estate, but whatevs.
5) I found the buttons nearly impossible to press easily. Maybe it's just me. Top power button is an impossible reach (all phones should adopt the double-tap to wake), and the volume rocker is pretty hard to reach into a pocket and find.
6) Speed: Nothing I can throw at this phone will cause even a millisecond of stutter. I can practically hear it telling me, "Seriously, is that all you've got?"
7) Camera: Definitely the achilles heel of an otherwise flawless phone. The camera itself is perfectly serviceable. It takes pretty good pictures, if you don't fancy yourself an Ansel Adams. If you can find a way to not compare it to its contemporaries, you'll probably be more than happy with it. If you compare the pictures side-by-side, even against an older phone like my Galaxy S3, the fidelty just isn't there however. Even at minimal zoom. Front-facing camera, however, is the best in class. As others have mentioned, it probably does take sharper photos than the rear facing camera.