+1 [8D]
Let a new friend fly my Sabre 35 last nite; he has a beautiful A/W Extra 300 74" that he really doesn't want to smash up; he flew the Sabre and said he could see how a plane like that would be helpful in learning 3D. It's a lot easier on the wallet with one of the small profiles, either foam or balsa. The balsa profiles probably fly a little nicer than flat airfoiled foamies, but either will teach you the basics for control inputs and orientation (orientation i.e. inverted flight and belly in hovering was my biggest problem).