bogbeagle - reflexing the ailerons helps by reducing the lift that the wing produces at a given airspeed, making it drop faster in the landing approach. It takes some of the "float" out of the plane. It also allows a more extreme flare before the wing stalls, allowing the pilot to reduce his speed more if he wants to. Full scale planes don't do it (at least not as far as I know) because designs that need to be STOL have flaps. Flaps are better at shortening the landing approach, but if they can't be retracted they mess up everything else. So for a model that wasn't designed for short/steep landing approaches, reflexing the ailerons up kills some lift without giving the wing tough stall characteristics the way that turning them down like flapperons would.