I put a Novak HV heat sink on the mega today, and it really helped out with the temp. Previously, the motor had gotten up to 180F. With the heat sink, I couldn't get the motor any hotter than 165F, and I was thrashing on it pretty hard in my backyard. The MM got up to 140F today, but at the track (when the motor hit 180), the MM never got over 120F. So, the motor heat sink is a success.