The Revo runs awesome on 4s with MM. My original set up was: MM ESC, Feigao 9xl, UBEC, TrueRC 4s 8000mah lipo pack. Ran absolutely flawlessly all the time.
Here are some video's of it:
http://www.youtube.com/watch?v=DXchJTm-jbM
http://www.youtube.com/watch?v=kzqH_QrTHVI
http://www.youtube.com/watch?v=S4ecFRHuPUs