Have you held an N4 in your hand? I haven't seen an HTC One up close, but the N4 really feels solid. Yes, there's the "what if I break the back glass" problem, but aluminum dings, too.

As for the camera, I dunno... My cell phone camera is mostly there for "target of opportunity" shots when I forget to bring my real camera, so I don't find myself swayed by 100% crops of an 8MP or 4MP image that I'm unlikely to ever need to blow up to a level where I'd see the difference. Unless you get down to pixel-peeping levels with something like this, I don't think you really see a lot of difference. And, for me, certainly not hundreds of dollars worth of difference -- that could be a new lens for my real camera!