I would stay with the OS line and forget the SuperTiger stuff. I've tried 3 different ones and all had issues with keeping tuned. They would run great for a flight or two then need retuned again.

Saito and OS engines are basically tune and forget with the occansional high speed retune for temp changes

Remember, you get what you pay for

See above, I've had OS engines run several hundred flights without so much as a hickup. My Saito 91 is the exact same way. I know of several OS46AX's and OS50's with several hundred flight on them and still making tons of power