I've stuck with T-Mobile too long. Their coverage around BNAshville -- or any place in Tennessee, for that matter -- is awful. If you're not within a mile or so of a major highway, ...fuggedaboudit. My friends are all over the map with their carriers (except T-Mobile) and none has the coverage complaints I do. The worst of it is that the places where I'd most like to have cell phone coverage for emergencies -- like out in the hinterlands while mountain biking and such -- I've got zippo.
I've been to AT&T and Verizon's stores and -- naturally -- they both claim their service is the best (so obviously one of them -- or maybe both -- is lying). Judging from the map at Dead Cell Zones, Verizon has the fewest reported dead zones but that's hardly a scientific sampling. Replies to this post won't be either, of course, but I'm hoping someone out there has the skinny on cell phone coverage in the mid-state.