I'm on this plan, and it's adequate but the service is pretty shoddy during parts of my commute (...no reliable 4G within a 5 min drive either side of Golden Gate Bridge?!) VZW definitely didn't have that problem.

I'm not sure if it's T-Mobile hardware or towers, but given I just use the phone to f around and am not reliant on it for work, I don't really feel it's worth trying to RMA or anything