I have yet to see a more precisely or well built motor than the Xerun V10's. Not to mention their workhorses that can take some serious punishment. I'm sure the MM motors are good, I just have no experience with them. Run the std rotor with the timing on the motor set to 30* and go to town!! Check the V10 thread in a bit and I'll have my most recent 4.5 set ups posted for a large fast track and smaller parking lot club type tracks.
AWD