Is it more important that your carrier have impeccible cellular service, or that they have the smartphone you want? In T-Mobile’s case, they don’t have great service or great phones, so they’re kinda screwed until they get the iPhone and expand their 4G network.
T-Mobile is the only major carrier left in the U.S. that doesn’t sell the iPhone, and they’re probably not going to be able to sell it anytime soon because the iPhone’s expensive and according to their COO, they can’t afford it.