I currently live in MA (Boston north shore area). DXW was using Metro for a while. Works great if you're relatively close to cities. In some parts of Northern NH where she lives, she loses service close to her house (for comparison, AT&T, T-mobile, and VZ all work there, however)
MetroPCS, IMO, is good for the price, but be aware that once you get outside of medium-to-large towns, the coverage won't hold a candle to any of the larger providers.