what's the best (fastest) rom for a sprint mogul?

[avoges]

Guys & Gals,
I recently traded my vogue with a coworker for this mogul because I was fusturated due to the lack of a hardware keyboard and wanted to play with wifi.. He had flashed it to 6.1 and the GPS works, however i've noticed that it's running out of memory all the time. I can be on windows live, have seven beta connected (for email push) and be talking on sms and eventually it will slow down and freeze when flipping the screens. Is there a rom out there that manages RAM more efficiently? He said he flashed it to a stock rom but I have no idea.... I miss the vogue which sucks because this is one cool (heavy too) device!