Battery capacity, and it being nonremoveable, worries me. But I'm willing to concede that battery life may be decent or good, based on real life usage.
I'm more concerned about the lack of expandable storage.
16 GB (11 GB usable) is miniscule. It really is. I'm coming from a 4S with 32 GB, which is already full. I'm not into cloud storage, and there's absolutely no way I could manage with 11 GB's. A couple bigger apps (aren't many HD games over 2 GB?) would already put you near max capacity.. that's not even bringing music into play.
This thing has an absolute gorgeous screen. Seriously, it's ridiculous. But is a display that important when the phone has such glaring negatives against it?
Speaking for myself only.. no, it isn't. And my last experience with HTC soured me on them as is, so even if I could get past my worries about the battery and storage, I'm not sure about this phone. I've got an upgrade in a week's time. I think I'd rather hold out another week after that for the Note 2 on the 29th.