You might try the January '03 (I think) issue of Consumer Reports. They had a big article on all the services. They ranked all the carriers in several areas (dropped calls, static, price, etc). They had five or six regions all around the country as I recall. Verizon was 1st or 2nd in every region. Cingular also did pretty well as I recall. Sprint was middle of the pack or dead last in just about every region of the country.
On a related note I have Sprint and I have had many dropped calls in Raleigh and Atlanta. Static has been aweful in a lot of places. I do have a samsung phone, however. I was told that if you ever get a dropped call, immediately push *2 and when prompted say "dropped call" and you will receive a $.50 credit per dropped call on your bill. Haven't tried this yet.
I have a friend who was fed up with sprint and all the dropped calls. He called to cancel his service and before he could cancel his service he had two calls with customer service that were dropped. When the Sprint guy called him back he was laughing and saying he'd be sure to cancel my friends service right away.
I do think the area of the country a phone is predominently used in and the type of phone one has plays a big role in how good one's sprint service will be.