I've had T-Mobile service for almost 2 years as my only phone (no home phone). Service is quite good across the greater Boise area including Boise, Meridian, Eagle, Kuna, Nampa, and Caldwell. There are a few minor areas where service is less good, but still adequate. Sometimes call quality is less than perfect, but typically only when calling another mobile phone with a different carrier. It's not as clear as a land-line phone, but it is certainly good enough for making / taking calls.