even the one with counter balanced rudder exhibits quite a bit of coupling. In fact, I don't the the counter balance has anything to do with it. Anyway, just mix it out. On my 9C, its just a matter of one mix for each aileron (providing they're on seperate channels) and one for rudder to elevator. I setup all my planes with these four mixes activated, even before test flight. Then I roll right to KE, observe coupling, land, add mixing witht eplane idling at my feet, take off, do it again until left rudder is pure. Then repeat with a roll to the left into KE, for right rudder, etc. THen do this again for pitch coupling. One or 2 tankfulls will yeald a well behaved plane. BTW, this really helps with rolling harriers, which a well mixed ultra stick will do quite nicely.