Hello everyone, I am moving to Boston area this month and have an unlocked iPhone 4 with me(from my home country). I was wondering which mobile carrier is better for my iPhone 4? I googled and found tons of people complained about AT&T having terrible signal. But I also found that T-mobile only provides EDGE, that is too slow for my iPhone.... It seems the only choice is AT&T. Would anyone please give some advices? Thanks in advance!!