T-Mobile's prices are tempting, but I'd probably cancel my service the very next day because of the sorry ass in building coverage. It's non existent, specially while at work inside the control room. I would know, I was with them for like 5 years.
I'll just stick with Verizon, I get great coverage everywhere! Elevators, buildings, out fishing in my boat, or when I'm hunting in the middle of nowhere in the woods.
My wife and I got the 5's with Verizon and have no complaints whatsoever. Great phones, super fast!