Just got the AT&T locked version for $300 last week to replace my 1020 (no problems, just getting old and holding less charge). No regrets. I am on Insider Production Preview ring, so the second AU build. I did a factory reset and fresh install after my backup/restore stuck me on the app list (seriously, no Start menu!).
The camera doesn't measure up to the 1020 on long distance shots, but it is about 10 times faster, and still (barely) outclasses other flagships like my wife's iPhone 6s. So it's great for family photos, less so for "art" photos.
The back cover does feel cheap compared to Nokia's classics, but I've got it in a clear TPU case, so whatever. I'll take replaceable battery and expandable SD memory any day over a thicker back cover. The hardware runs rather warm during heavy use but cool during light use. I easily get a day's battery life, though (I'm at 77% right now after 20.5 hours of uptime, this has been a relatively light weekend day, though). The display is beautiful, and the overall aesthetics of the phone are very nice (I can't believe I used to hate the camera ring).
I'm not all that into the latest apps, so I'm satisfied with MS native apps (the excellent MSN News, Sports, Weather, Office) and what MS has in the store (Facebook +Messenger, Fitbit, Nest thermostat manager, Flipboard, NextGen Reader, MetroTube). Edge makes up for most other gaps and is a definite upgrade over WP8.1's version of IE.
Overall, very satisfying to this WP fan (900, 1020, 950), especially at the reduced price. I'm very glad I waited, though, as earlier W10M builds were not good enough (I have a 640 as a testbed/music player, so I'm quite familiar with W10M's progress) and the initial price was too high. I get why a non WP-fan wouldn't switch, but for me, it's a nice move from my 1020.