Motorola V600

My wife and I have a family plan on ATT with two v600's. We are considering upgrading to the moto v3 because we like the mini usb charging feature(the v600 charge connection seems to be very touchy). I can get two v3's off of myrateplan.com with a two year cingular family contract for $200. It sounds like a good deal but I do not trust phone companies. Is there anything that i should know? Anyone have any stories to tell me about the switch from att to cingular. It looks like the plan is identical, but who knows?
Any help or advice you guys could give would be much appreciated!