RE: U.S. AirCore 40 Trainer Kit
I have seen several of these take a real beating, one (it was a Colt 40 not the trainer) dove in after a loop at almost full power, that plane flew again the next week, with about $5 worth of repairs.
That said, they are very heavy and need a bit more power than a regular .40 can provide. I would overpower the plane by a bit if you are going to buy one.