It is not as good as AT&T or Verizon, but for $16/mo with 3GB of data it's hard to beat. Also, they really don't care much about what phone you use, as long as it supports VoLTE, which is what motivated me to switch off AT&T after decades.

I've not had problems with service in Leominster. What I'd suggest is getting a pre-paid SIM and just driving around to your most important locations to check service. That's what I did before switching.