I’ve got the One.
Its a great phone, powerful, fast, good battery life. Great camera. well built, feels nice in the hand. I find the audio through the built in speakers to be much better than any other phone, but how often do you really listen through the built in speakers. audio through the headphones is the same as any other phone.
Cant find any significant faults,but I guess the fact that it doesnt have an SD card slot could be considered a downside.
regarding battery life, I get 2 days of what I consider to be light use between charges, thats with push email switched on, a few phone calls, and a bit of surfing. With heavy use, it’ll go the day for me, so no complaints there.
I think the samsung galaxy S4 is slightly faster (according to benchmarks), but you’d probably not notice the difference in real world use.
If you like the sensation and the way the HTC sense software works then I cant see any reason why you wouldnt like the One.