The MM works great with a 2650. I am running my 3year old MM and CC 2650kv in the 8ight - 1/8 Buggy. Which is like 9.5 pounds. The Slash 4x4 cant be over 7.5... Go for it. Good Combo
I am running 4s, and geared to do 47-48mph. The MM works very well with either an external BEC or Reciever pack. If it is getting a bit warm. Add a Fan.