Mystic. I built a GP Ultimate last summer, powered with an FX46. 11x5 APC prop.
Tons of power. Wont hover, at least not for me, but all else is great. Flies great. Watch the elevator throws. I set mine by the recommended amounts in the manual and almost lost it on first take off. Straight up, straight down and up just in time to bend the landing gear but saved the plane.
Did have a lot of engine problems that turned out to be overheating and subsequent leaning out. Ended up covering the front hole in the cowling opposite the cylinder. Much better after that. Go figure