Dick, do you have a site for the airplane you mentioned or some locating material. It sounds interesting.

Paul's data points are really interesting. It takes more courage than I could muster. Of course it could mean that the original airfoil was the dog of the century!

Finesse in airfoils pays off when you are designing for full scale long distance load carrying machines. There a few counts of drag saved converts directly into dollars saved. When we were doing the F-15 wing we spent a lot of time trying to get a compromise that lowered the drag and hopefully still hung on in the high load factor transonic region where buffet onset is a real problem. Even then when we went into flight test we tufted the upper surface to the wing to see where the air was going. It was interesting stuff.

Finesse in little light airplanes sometimes is wasted because we just can't evaluate it from the ground. You can measure roll and loop rates but beyond that every feedback from the airplane is through the eyes. Not the most precise range finders around although they arn't too bad. You can get a feel for landing speed that isn't too bad but anything else is really tough to quantify.