I just finished my Predator and flew it this past week end. I have an O.S. .25FX on mine and it flies great! It's very fast and do not exceed the recommended 3/16" elevator throw. I had mine set at 5/16" and it would snap out of a loop. My only suggestions are to pre-stage the components to set the CG before gluing everything in. Even after putting the Rx and tha battery just behind the front brace my engine ended up at the very end of the mounting beams...

I built mine pretty much per the instructions. I did cut out the squares of foam shown in the instructions to increase roll rate, and I used the bi-directional tape all the way across the top of the wing instead of stopping at 2/3rds span. Mine is very stiff and with 1/2" of elevator thow the roll rate is very fast.

I can hand launch mine myself as it pretty much flies out of your hand when you release it.

Cheers!

Galen