There's an interesting article in Model Aviation this month by Dave Scott. He advocates the use of vortex generators as a way to make control surfaces more sensitive at positions near neutral.

The reasoning is that under normal circumstances, there is a 3-4 mm layer of turbulence along the surface of the wing. At small deviations, the control surfaces are still within this turbulent layer, which reduces their ability to generate force smoothly. By adding vortex generators to the wing, the turbulence is disrupted. This reduces the stall speed of the wing and gives control surfaces more effectiveness. The price is a slight increase in drag and reduction of top speed (1%). There's a mesmerizing video about testing vortex generators in a full-sized plane here.

So my question is whether anyone has tried these on a pattern plane to see how they affect control for small stick inputs. My guess is that it would be icing on the cake, and make little difference for someone at my (modest) skill level. But I found the idea intriguing.