I think there is going to be different opinions on this subject simply because we have differnt views on what performance and stability mean. There really is nothing saying that additional dihedral will reduce aileron authority. It will however create a control cross couple. Many of us long time R/C pilots with little to no full scale experience tend to Veiw stability as the airplanes capability to go where pointed and stay on that line. Full scale guys think as stability in term of the airplane being able to somewhat right itself. One trend I see which full scale guys is the misconception that aerobatic airplanes must be less stable, more difficult to fly and are snap/stall happy.