Exactly. Turning the wing over will help a LITTLE but it sure won't turn a fast "stally" model into a soft trainer like kitten. Espeically if they are overly heavy already as rmh says. Moving the CG forward by shifting the battery back is likely your best option. I don't know if you would need to go as far as to 20 to 25% but you certainly want to move it forward about 3/8 to 1/2 inch from where it is now. If that puts the balance to around the 25% point then so be it. It all depends on where it's starting from now.