I have T-Mobile and a guy at work always rags me since the merger saying I'm on Metro. I live and work in the Tampa Bay area so both T-Mobile and Metro have 4G/LTE service here. A few co-workers have Metro and I always kill them on speed test. In fact some of them need to walk outside just to make a phone call or download something while I can do it all inside without any loss in service.
In fact the guy who rags me is on Verizon and he now shuts his mouth since I also destroyed his speed test results.
I really just think it has to do with Metro.