I personally will never do business with Sprint again. Worst customer service I have ever had the horrible displeasure of dealing with.
We were with Cingular when AT&T bought them out. Love the roll-over minutes. Never ever have had an over-use charge because of them.
However, we are both tired of having no service when we go out in the woods or to obscure beaches. We go canoeing and our phones are useless before we even get to our put-in spot. My buddy with Verizon? Oh, he's floating down the river, drinking a rum & coke, surfing the internet. Personally, I don't want to surf the internet while I'm canoeing, but having the emergency connectivity sure would be nice.
So I think we're going to go with Verizon next. No complaints about AT&T/Cingular though, except if you spend a lot of time out in the woods and want your cell phone to work.
Here's an interesting website to check out....
http://www.wirelessguide.org/plan/service-comparisons.htm