Superstar has more dihedral in the wing making it more stable. I also believe the Superstar has a more flat wing shape making is more predicatable in the air. The Avistar has a semi-symetrical wing which allows more maneuverability. It has has less dihedral in the wing making it a bit quicker. The Avistar is categorized as a Advanced Trainer. Hopefully I explained it right if not someone please correct me.