The HTC One is great. I have had mine for a couple of weeks now and I am loving it. I moved from an old Droid 3 to the HTC one when the old beast would not boot. Everything about this phone is great as far as I can tell. Things are all snappy to launch and the sound is all great.
Treo 650 -> Trep 700p -> Disposable Handy in DE -> Droid -> Droid 3