Verizon drives us insane with their billing fiascos. I think they operate on the infinite monkey data entry principle, or "drive customers crazy and they'll eventually stop complaining & just pay for mistaken extras." Their agents aren't impressive, and pay more attention to their scripts than the dialogue. Good coverage, but be careful. Avoid any shared plans as those seem to invite billing nightmares.
I've been pleasantly surprised by Sprint. I hated them in the SF bay area. (a couple years ago.) It was especially stressful managing our small company's plans. Coverage, support, you name it. Trying them again here in Oregon because of their data plan. So far I've made 8 calls to their support people at different times of the day. Call it the two week test. Each time it has seemed like I was calling a center in N. California, and agents who were strangely interested in talking tech. With my luck they use a special department for the first 14days until you can't cancel without penalty.
Anyway, not much history yet but two bills in things are going smoothly. Samsung A900 phone is beautiful.