I fly a SIG wonder/OS 15FP. It has a 2 oz tank, 2 mini high speed sevos and S148 (Futaba) on the throttle. It must have 200 to 300 flights. They aren't fun to fly in the wind. I think I have test flown Wonders with at least 10 different size engines. I spent quite a bit of time developing a routine whereby I start the engine, switch hands, extend antenna, and throw myself. I belive mine weighs 34 ozs. It has a 27o maH battery.