I've had the iPhone & AT&T for a month and a half now. I've only had a couple of dropped calls, and I was initially very worried about this.
Even better, my call quality is MUCH better than Sprint. My wife actually had to turn her volume down because I was coming in both louder and clearer. I'd had Sprint since the mid-90s, and had good service with them both in Atlanta and in St Louis. I've been pleasantly surprised with the quality of the service here in St Louis (suburb of O'Fallon).
I've noticed that most of the posters in this thread don't have their locations listed, and most didn't mention where they are.
So, where are you folks having trouble?