I am flying the Pizazz with an OS 60FP 2C. Plenty of vertical, even though mine is quite a bit heavier than most. This is because I got mine free from a guy that wrecked it and didn't want to rebuild it. I'm still tweaking the CG back. I have it 1/2 inch behind the spar now, and it still looks like it needs to be back more. Does great knife edge.

Your Sudokhoi problem really stumps me . I am flying mine with a stock, right out of the box OS 46FX and I have vertical like a homesick angel. I've used 11-4, 11.5-4 and 12.25-3.75 props and had great results with all. My weight isn't super light on that one either as it weighs 4 lbs 9oz. I would assume that with a 50SX the Sudo should scream.

My fuel is 15% Byron and I like OS No. 8 plugs.