T Mobile wifi Phone with Verizon data coverage?

T-mobile as I understand uses a different system. Data is still carried over the cell network. So I don't see you saving anything and ending up frustrated because you get zero coverage on t-mobile unless your within 20 miles of a big city. Friend has t-mobile and gets lousy service at his house in town. Drop three of the phones or get 4 basic phones for everyone but you. Cut data amount or go to 5 pay as you go phones