You still definitely have to think about what kind of coverage T-mobile is going to give you in the places where you need it. But work coverage might be perfectly fine. I had a t-mobile prepaid flip phone in 2005, and we used to have to stand in particular spots in the house to make a call with it. Now we get very solid coverage all over the house and neighborhood (a planned community between Redmond and Duvall), but I do encounter coverage gaps in some shops and restaurants and things, and cycling out beyond our community - exurban areas, not rural). But I attempted Turtlehead Peak in Red Rock Canyon and got coverage most of the way up, and in most of the Red Rock Canyon area.

The T-mobile pricing is great, and their responsiveness to customer complaints seems to be great too. The T-mobile One was just stupid when they rolled it out. A substantial price increase, severely compromised hotspotting, and unlimited that was not really needed because BingeOn and Music Freedom made the biggest data consumers unlimited anyway. And now it is a really good value, and as close to true unlimited as a wireless carrier can be, so long as resources remain finite.

Coverage has to be taken into account, but if T-mobile coverage works for you, I think it's the best choice