I've used several electric drills with my MM3... They all worked ok but speed was a bit of an issue (as in they went too fast). I finally ended up getting a DEWALT DWD210G 10-Amp drill. It has much lower RPMs and much higher torque than my other drills. I am able to control the speed and go nice and steady when crushing my grains now. I get a much much better crush with this drill vs the other ones I was using.
You get over that hand cranking "organic connection" with the grain real quick after you hand mill a barley wine. I spent the extra money and got a high torque drill, too. It hardly breaks a sweat, very consistent crush, It's one of the smartest purchases I've made. (If you're married, tell your wife you need the drill for projects around the house.)