I've seen mention on here that there might be call for thinning out wings of electric models over their glow counterparts.
Right, several guys here got idea to save power and energy with thinner airfoil. Yes, it is true, thinner airfoil has lower drag, but that thinking has one small hole in logic: thinner airfoil also make less lift (maximal lift coefficiet), it means wing must be larger for the same weight and since the drag formula has also wing area as a parameter, the drag of larger wing will be aproximately same
but there is also another reason for thicker airfoil, thicker airfoil has more drag in level flight then thinner one, but thinner will go to larger grags in maneuvers (partial stalling) so thicker one can keep better speed stability in corners and that is what counts in figures.
the same is with airfoiled flaps, such an airfoil has low drag in level flight, but it slows in corners, it is well visible, I can tell from 100 meters if the model has NACA type airfoiled airfoil or my with thinn hingeline.
if you ask which is better in real world, it is hard to say, because some people need corner done like with knife in butter, and some simply need that stopping in corners