I've had them all over the past two years. I live in AZ, work mainly in DFW, LAX,
SFO, SEA and SYD.

I don't go with a carrier for a free phone; I buy a good phone and am concerned only with good coverage and accurate billing. If billing is correct, there's no reason to contact customer service.

All Carriers' Customer Service Stinks!

Sprint - signal extremely poor in PHX, LAX. Major billing headaches from errors related to roaming. Can't use in SYD
Verizon - many dropped calls, spotty service coverage in PHX. Can't use in SYD
T-Mobile - spotty service everywhere except SYD
Cingular - Best coverage of the bunch, best data services of the bunch, no roaming charges. Great int'l rate program - get killer service in SYD at reasonable rates.

Have been carrying a Treo 650 since January with Cingular, haven't considered changing at all.