I recently switched to Sprint from a regional GSM carrier. Although their Customer Service leaves alot to be desired and I believe that is mostly due to their phone system and the fact that their CS facilities are scattered all over the place. I have learned that if I call before noon EST I do much better with CS. I have also noticed that CS has gotten considerably better in the short 2 months I have had service with them.
The plans are awesome, so much so that my son has also come over to sprint and he has much better coverage with Sprint than he did with Verizon here in rural northern Indiana.
Sprint gives you a 30 day money back guarantee for both the phone and service so I suggest you give them a try before canceling your Verizon account then you can make an educated decision on your move.
Also I have a family Everything plan with 3 lines and am saving a good chunk of money over my old provider. My son has the 450 Everthing plan using a Blackberry and it's only 69.99 w/7pm N&W which is also considerable savings.
All in all I'm very happy with Sprints service, I just watch the time of day that I call CS.