I used to work for Sprint about 8 years ago. So they have changed a lot since then. Back then there customer service was dead last, but now I hear they are number 1 in customer service. I rarely call them for help. But the times I have they are helpful.
Coverage has been fine, there are some dead/weak areas. For example above the capitol area. Bountiful has some weak spots by the mountains as well. But other than those main areas it's been fine. I just use my phone for voice and some texts. So I can't comment on the data speed and availability.
Plans price wise it's ok. I still think cell phone plans in general are over priced.