I switched from a V3 razer too. I also switched from ATT/cingular/ATT whom I was with for 7 years.
I switched to T-mobile because of the superior rate plans. You just can't beat the my 5.
However, I have poorer tmobile reception in my area than I had with ATT.
So the clincher for me was when the 8320 came out because I could use the h@h to have better service.
As with all new things, I have run into bugs/issues. However once the h@h issues are fixed you simply just can't beat the 8320. It's been a great phone for me.