You will not have any "handicap" from using a Magnum, and dont let anyone tell you different. I have a friend who flys a Don Smith Constellation on 4 Mag 91's and they are extremley reliable. If they were a handicap, I dont think he would put a mege$$$ bird up with them. However, if you use too large a prop to slow the motor (any motor) down, you can expereince overheating. You need to prop the motor to run at it's most effecient RPM to have good reliability,& power. The "dog" is right about four blade props, in most cases they do not work well.