This is the only reason I switched to T-Mobile originally and the only reason I still have them. Their coverage is so poor that I get no LTE service sitting in my house in a core part of the major metro area. I'm only able to maintain them because they were an early and ardent adopter of WiFi Calling. On a recent trip in the US I had no service off major interstate highways. Internationally though, T-Mobile is amazing. I honestly wish my experience in the US was as good as my experience while traveling... there's not much point in having uncapped LTE when you get 1 or 0 bars of service, at least internationally I get great service even if it is speed capped at 256kbps.