So... I hate Cingular. I like GSM, and I liked the phones I had [both stolen/lost] but unfortunately Cingular's subpar customer service and expensive rate plans mean now that I'm back in the west, I'm back with t-mobile. I know its going to cost me $175 to switch to t-mobile, and I know this means I've spent over $1,000 on cingular phones/service fees, but its really worth it.
For my mobile dollar, T-mobile is the best. That's all there is to it. $1,000 later, I can confedently state that T-mobile = the bomb.