Thank you for all the good info. I would consider myself an intermediate pilot, more slope soaring with composite gliders than power though. I fly at my house, I don't have any input from other expirienced pilots, so I will be relying on the comments posted here. I have a fun 51, wich I can hover and flatspin quite well with, so I think I am ready to set the passion up for more serious 3D. I decided to use the .75 because it was lying around. I should be able to get good enough power with it, I live at sea level and use 15%. One person on here measured 11.4lbs of thrust running an APC 13x4 at around 12k rpm. I believe the passion is 5.5-6 lbs wet. 13x4 seems a little small, but I will give it a try. Also thinking of an APC 14x4W, any Comments? How much throw should I set spoilerons and flapperons at? Also, should I add in some flap to elevator mix (flapperons down when I pull back on elevator)? I will start with the CG at the recommended spot or slightly behind for starters. I beefed up the tail structure, landing gear and firewall, so It should be sturdy enough to handle the forces.