Hi Bob: No I haven't and my LT-40 is anything but docile. Look at the plans and see that they give you 3 different positions for the CG and all I did with mine is move to to the furthest one back for advanced flying. The common problem I see is people balancing the plane way to nose heavy and this will make any plane sluggish. If you put the CG back a bit more then what they call for for the beginner you will find it to be a nice plane that shouldn't give any problems with the transition.