re: How good is Spint's service/network?

It can be bad in certain areas just like any provider. It all depends on where you are located and where you require the most/best service.

For example Sprint at my work and home are excellent and even performs better than several other providers at these locations.

Sprint in BR is about as bad as it gets that is why you do not hear good things about them here. And this is something Sprint desperately needs to focus on with their network overhaul.

Outside of BR Sprint can be viable and is a decent value depending on your needs.

Expect Sprint to keep improving as they continue to roll out more spectrum. Although BR is pretty much screwed in the near term unfortunately.