I had AT&T for 2 weeks with the 3GS and loved the phone and got to Johnstown and lost service for an entire weekend. I went back to Verizon and have ordered the iPhone4 and can't wait to get it. I don't care what phone I have, how expensive they may be compared to other carriers, for 10+ years, I've traveled from here to Cali with no more than a blip in service, reception or teathering. THAT is why I'm staying with Verizon. Is Sprint comparable to that? I have no idea but AT&T was NOT even close when it came to reception. TMobile? No clue.... but Verizon is tried and true in my eyes, no matter what phone I'm using.