i have the 50cc and 100cc extra. The 75cc is a larger version of the 50cc with many of the same features such as single servo wings/ailerons. The 100cc does fly better, but it's a little more costly to get in the air. With the 75cc, you can get away with single servos on each flying surface whereas with the 100 cc, there are two servos on each aileron and I used 2 servos for the rudder as well. So, if you can afford the extra $ for the larger motor and more servos, go with the 100cc. If i had it to do over, i would definately use the DA 85cc on the 35% extra.