the trouble with comparing cellular companies is that their service and service packages vary from location to location...
I used to have AT&T, and the service in Houston was the worst of the major companies...
I now use Cingular with a Samsung GSM phone (I programmed it to play Rush's "Red Barchetta" when it rings...), and on the plan I have cell to cell calls are free.
But, YYMV (and it probably will)
We can do it my way, or we can do it my way while I yell. The choice is yours.