I have a friend who soloed on an old Air Vista (Hobbico I think) with only 5 flights under his belt. I have another friend who is struggling on a Dynaflite Butterfly. Different strokes for different fokes. I believe there are students who can handle the "hotter" trainers with ease and some who will struggle to fly even a slow docile trainer. The tough part is you never know someones flying skills until they try there hands at flying. If it were possible I would have every newcomer to this hobby fly a typical 4 channel trainer (w/instructor) 3 times. If they are starting to get the hang of it you will know by the end of the 3rd lesson. If they are still struggling then they may need a tamer trainer. (ie Sig Kadet Senior, Dynaflite Butterfly) As always, just my opinion.