I like aerobatics but i still want something that I can just cruise around casually. Whirley Bird after having a fourstroke I dont think I could ever go back to a 2 stroke, unless it was a gas burner. Just the sound alone is enough to have one in my opinion. The os 70 in my colt flies it very well. Four strokes are a little harder to tune by ear so a tach is usually needed.