I hope this helps. I am a Cingular Agent and just bought the Z520a. I have a Motorola V3 as well, but I really liked the look and functionality of the Z520 and wanted to give Sony Ericsson a shot.

I changed service providers and after reading several reviews I chose the Nokia 6263 to replace my Sony Z520. I used the Nokia for a little over a week and promptly switched back to my little Sony.