I've been a Sprint customer for 8 years and although my impression of their coverage has waxed and waned, I never thought it was any better/worse than the other carriers. Customer service was never great, but it was never outright bad until this past year when I was having trouble with my Treo 600.
I took my very expensive smart phone to the Sprint store after being told over the phone that it needed to be tested. This was months before my warranty had expired. It was telling me that I had No Service when I could clearly see 3+ bars of signal strength. I took the phone in and they were not able to detect any problem. Over time I noticed that the problem only occured after the battery had lost a little of it's charge. I took it in again the month before my warranty had expired and again was told that there was nothing wrong.
Weeks after my warranty expired, I took the phone in again ... it was driving me nuts that I couldn't place a call and most of my incoming calls were being immediately dropped. THIS time, the technician said almost immediately that it was a battery wiring issue and that it was a known issue. But since the phone was now out of warranty, he could do nothing to help me.
I thought I would call and talk to someone at Sprint that could help me ... to no avail. They have made their entire customer experience about sales. If you have a problem to discuss, they coo softly and tell you to go to a Sprint store, where they are seriously understaffed and unable to do anything to keep customers happy.
At this point, I am looking at the Treo 650 (although I just heard that the Treo 700 will be out soon) with either Verizon or Cingular. Since I still have another year on my contract, Sprint will not even give me the upgrade rebate. The way I figure, I can go to another carrier, pay the $150 to get out of my Sprint contract and end up with pretty much the same cost as buying the new Treo on my existing contract.
I hate to sound like an entitled snit, but after 3 visits to their stores inside the warranty period (which they have recorded, but never for the reason I stopped in - each contact record says they offered my new services or products and includes nothing about why I stopped in), you think they would do more to keep a customer with 8 years of history.
Look for my posting seeking advice.