CG is 3 1/2 inches from the leading edge, taken at the wing root.

The guy I had the midair with had the .50 SX on his too.

I never notice the expo now. If you set it right, you won't notice at all. It is very smooth from center to full throw. The good thing about expo is that you can set it where moving from low rates to high feels the same until you really move the sticks around. It is sort of seamless when you get it right.