ORIGINAL: ndb8fxe
A company I used to work for had 6 Grumman Tigers that we flew in formation. One of them had a modification where they cut the taper off of the trailing edge of the ailerons leaving a squared off TE. Out of the 6 planes this plane had the worst flying qualities. For one it was noticably slower than the others. And two the controll pressure to get the plane to roll was incredibly more than any other Tiger that I've flown. This made one of the nicest flying Low Performance singles unpleasant to fly.
With a model? I don't know, I imagine there might be an increase in pressure to move the ailerons and possible a speed decrease.
However the current plane I am flying (a large corporate type jet) does have squared off trailing edge at about 1/2 inch for a 60 ft wingspan. This plane also is not sensitive/responsive to control inputs. This plane however is Fast! Not sure what conclusion to draw from it.