I'm on the Sprint Basics rom. It's a 6.1 rom trimmed of the fat. The kitchen is available as well, so you can make your own customized version. It's very fast, and battery drain is minimal. No matter what other roms I try, I always come back to this one because you just can't beat the simplicity. And I just started running Mobile Shell on it, so now it's even got a nifty interface that doesn't hog all the resources.
http://forum.ppcgeeks.com/cdma-tp2-u...-6-1-only.html