I would have to disagree. You are correct in that wing loading is extremely important, but there are two sources that create increased wing loading. 1) heavy airframe/payload and 2)high g turns. Obviously for something like a pattern plane airfoil section is going to be more critical than that of a trainer because they are trying to optimize their lift vs. drag in a high alpha turn. So simply adding wing area might help with the turns, but kill them on the strait out runs. Models such as trainers and such are not flown to their design limits, but pattern, jets, and similar aircraft are routinely flown in an environment where airfoil choice is very important. I guess the differences might be minute, but at 100+ MPH it could make or break the run.