That is an excellent point- choosing a plane that the instructors are comfortable teaching on helps a lot in the process! My club is predominately glow flyers but the occasional Super Cub shows up and the trainers work with them. The negative for more serious pilots is that without ailerons, the options for learning aerobatics are very limited. But for a 9 year old who will probably be amused by just flying around in circles for a good while and who would be quickly discouraged by long repair times, I think it's a great choice.