ATT is bad BECAUSE the iphone. Its a crippling monster. It beats up there network. Apple didnt expect the sales they got, and therefore att did not upgrade there network in time. now they are behind because of there smartphones. Verizon was the first company asked to take the iphone, but they declined because they didn't know what would happen to the network. They just watched what it did to att and built up before releasing android phones. verizon built a multi-million dollar open source cell phone testing center for android phone develepment.
I really hope they dont bring the iphone to verizon, but I do trust that if they do, they will invest in the network to make sure it will hold.