Pete,
There is more information on the Wayne Mackey Stolquest SQ2 in the July 2010 issue of EAA Sport Aviation which is a special STOL issue with several cogent articles. I didn't have the issue initially at hand when formulating my first reply. One of the articles discusses the strange aerodynamics of the STOL flight results achieved by Alaska bush pilots, i.e getting lift from the bottom of the wing? Answer is explained.
Also, see YouTube for videos of the Valdez, AK STOL Competitions. Pretty amazing performances must be seen to be believed