I really Like O.S engines and prefer them. But for every guy that says O.S is better there is another guy to say Saito is better. I have found that with just about everything in this hobby your best bet is to talk to the guys at your field or club and fly what they fly. If you have 10 Saito experts and no O.S experts it might be hard to find help with a brand specific issue, tuning, breaking in etc. I try to use what the guys at the field use because there experience cannot be matched.