The first phone/carrier I got as an adult was an iPhone 4s from Sprint, and I basically didn't have service for 98% of the phone's life. Then again, the merger probably means a larger network overall.
They should also have a service agreement with Verizon, giving them at least some additional coverage; though I'm unsure how much 3P are discriminated at the tower.
Nah mate, we'll still run it in prod for 5yr+