I have to say (my apologies for getting off subject) that a couple of SPADs my dad and I have built have been some of the most fun I've ever had at the field. As for learning from planes, I'd say I learned the most from planes that behaved badly. An overweight E-Z Bee (who else remembers the days of learning on a Cox powered plane with a porky AM radio?), an intentionally aft balanced durabrick, and highly modified SPADs that were nearly all control surface, just to name a few. Of course, none if this stick time I have would be benificial at all without the proper primary training. I think one of the biggest mistakes a person can make in R/C is advancing too quickly. There is no reason to sell a trainer until it is absolutely raged out IMO.
-Steve