I guess people rate whether planes fly well in different ways. My rating system values smooth maneuvering, slow landings, consistent control response, no weird coupling issues, moderate wind tolerance, and basic aerobatic capability for trainers. I want my students to have a plane that is light on the wing and does what the pilot wants it to. You get that from a Sig Kadet, Hobbico Avistar, and a number of others. With the Super Cub you get a plane that will fly in a straight line pretty reliably and do turns it if has to, but forget rolls or loops of any size. The Bixler and others like it aren't even that capable, and can be quite frustrating for pilots who truly want to learn piloting instead of just watch a toy buzz through the air.