I really like my iPhone... i'm not an apple fanboy by any means since i've never owned any other apple product outside of an ipod, but I am very impressed by the iPhone. It has pretty much everything that I need in a cell phone, and I really don't need anything else for my needs at least. Well, I guess if it had GPS than it would be perfect.
I also don't have any problems with AT&T, but I guess some people do. I get the occassional dropped call, but nothing too bad.