I'm flying a SE with the OS 70. Seems just about right, plenty of power, unlimited vertical, knife-edge at 1/2 to 3/4 throttle, high rates are awesome. Can you tell I like this airplane? Others I've talked to with smaller (read lighter) engines have had to add lot of weight. Prop clearance can be a problem. Also...as you are probably aware this is NOT a beginner's airplane. It's ok as a second or third however.