ok. the manual says 7 7/16" back from leading edge of wing measured at fuselage. mine is at about 9 1/4" and flies perfect. if you are balancing anywhere in between that range you will have absolutely no problem. mine still flies easy and docile when on low rates, (which barely ever get used) and is a blast on high rates.

My setup is

Rudder- 7 1/2" measured at back and bottom of rudder
Elevator- 3"
Ailerons- 3"

the book says more aileron but all you get from more is a faster roll....and how it is its all ready faster than you can correct because you can't see where it is to correct it. and in a hover it will still roll with or opposite tourque with no problem or hesitation at all.....elevator is slightly less than the manual but it was way more than the manual said untill i made it more tail heavy and as you move cg back elevator has more effect, so that 3" has more effect than the 3 3/4 did before.