[Snowbirdtobe]

I have the Sprint 4S and I'm not sure that the telephone sound quality is as good as my old 3gs.
Here are the data rates from the same spot near SS at 10:30 PM for ATT and Sprint.
Att 1.61 Mbps download 0.21 Mbps upload 698 ms ping
Sprint 1.16 Mbps download 0.85 Mbps upload 214 ms ping
Here are some WIFI data rates.
Comcast WIFI 7.42 Mbps download 3.84 Mbps upload 149 ms ping
Sprint Wireless store WIFI near SS
5.31 Mbps download 0.85 Mbps upload 76 ms ping
I expect that Sprint will have the same dropped call problems that ATT had when the iPhone first came out. For much of the drive from Massachusetts to TV we had no ATT service but our old Sprint phone had service.
I was a iPhone ATT customer from day 1 of the phone. I switched from Sprint to get the phone.
Verizon was not attractive since they don't cap the cost of the data transfers and I was grandfathered into unlimited data with my old ATT plans.