I have AT&T, Visible+, Metro BYOD, and Helium (Grandfathered at 5/month) and I think my best overall plans have been my t-mobile mvnos (Metro and Helium). AT&T is really solid for coverage while maintaining speed and Verizon (Visible+) has been the worst out of the 3 for me but I keep it because it also depends on location. In some places like all carriers Verizon has the upperhand.