I used to fly a GP60 size cub and I got rid of it because I did not like it. I am presently finishing the sig cub and boy is this one heck of a kit. As far as the GP goes it is very heavy, and does not fly like a cub. Yes the sig cub kit is balsa but I would not go as far as to say that it is not as durable as the GP. Lite ply is used because of the high cost of balsa wood not because of the strengh. No matter what kit you build you still have to be a pilot, I do not build them to crash, I have robart landing gear on mine and boy does it look scale. As far as having to use rudder cordinated with the ailerons that is how a real cub flys. The quality of this kit was out of this world as far as I am concerned. I have built many kits in my life and this is the best I have ever seen.