Personally, I think control reversal is 90% of the battle. I self taught my self with the Aerobird. It wasn't pretty at first. Once I got used to control reversal it was easy.

I have a glow trainer now. Just started flying it 3 weeks ago. Ever once in a while, specially on taking off I noticed my "instinctive" control reversal needs some sharpening.

All and all, I do believe control reverson is the toughest part. Just my opinion. Even now with my glow plane I am not that comfortable doing any manuevers unless the plane is going away from me.

Wings.