While it doesn't impact me, I spent a few years in Iowa, which has pretty junk coverage from every carrier except US Cellular. I was surprised by how many people used them in Iowa (and that they had the most store-front stores around). While you'll get coverage along the major highways (which means all the major cities have coverage from AT&T and Verizon), when you start driving into farmland, US Cellular is the only option.

There are definitely places where this US Cellular is the only option, and this is an awesome addition for those people.