ORIGINAL: combatpigg
A flat slab control surface takes less deflection to get into the airstream from center. This should contribute to responsiveness and detract from smoothness.
A tapered surface has aerodynamic exponential. I think this is covered in a book written by Dick Mathis.
I doubt I could tell the difference on a RC sport model, but I'll bet a C/L Stunt Guru could tell the difference..
This is simply not true. The flat slab and the airfoiled surfaces are fully wetted which means control inputs will be felt regardless of how small. The comment above implies that the free airstream around the wing or stab somehow is separated from the surface and it takes distance of travel before the control surface gets into the airstream.
Of the two, the airfoiled is more efficient in terms of lower drag
MattK