As far as using the service, I can't tell any difference over AT&T which costs over twice as much. Their customer service is horrible. I had AT&T before moving here.
Several people have told me US Cellular is the best here but I guess they roam on other networks outside Oklahoma? That's what I was told by someone that uses their service...haven't looked to see if that's true.
If you are in pontotoc county near Francis, then yes US cellular works best out that way, esp on hwy 99 north from byng onwards.
ATT works pretty decent out that way compared to many years ago, but theres a lot oh hills and bottoms out that way to deal with.