First flight was great, need to dial in the cg and throws. Engine ran great I would say almost equivalent to the OS 1.40 and after breakin and tuning will be as good. Not a DZ 1.60. But for me flying sportsman plenty of power. I have an Impact with an Os 1.40 and cannot tell any difference in power. Smooth is the word the engine runs very smoothly and I thinks vibrates less than the 1.40. These are my observations. The plane was flown by others who had positive comments. You can fly 15 minutes on less than 12 oz of fuel just one of the benefits and fuel is alot cheaper.