I learned to fly with an Avistar, and to this day I think they are the best plane to learn on. There also the best beater plane around. I've had several, and in the wind, their the greatest !!!
I don't know about the newer one's, but the 2002/2003 Avistars ROCK !!! And I don't remember adding any weight to any of mine, they all flew amazingly well. By the way, throw away that 40LA and install a Saito 56. You may need a little tail weight then, but you won't be sorry...... Dennis Flora