I am located in Alaska and own a business called Fly Around Alaska. I teach off airport/ bush flying. To date I have given around 3,500 hours of dual to people in their Cubs. These Cubs have every modification on them and I know them all well.
I also have the Artic's Air Junkies exhibition, experimental Nolen 5. It is basically a wide J-3. Originally it did not have flaps and I had Gurney flaps mounted to it. It was a very slow flier with the Gurneys. I won the third place spot at Valdez that year. The stall speed was around 35 mph. The pitch angle was pretty unruly and I would always bounce the tailwheel on the surface before the mains. Then I researched your VG's. I liked the fact that they had round tips and I could use my wing covers. I also threw some math at it and figured they would do better than the other VG's on the market. Boy was I right. We added the VG's and made flaps out of Taylorcraft ailerons. The flaps slowed it down to about 32 and your VG's knocked off another 6 mph. I stall around 26 now. What is even more amazing is I put them ahead of the rudder on the stabilizer. I can now slip at angles unheard of and without fear of airflow separation spanwise. It is pretty amazing what they have done. I also don't have 3,000 dollars worth of slats in my way when I am putting gas in.
Thanks for a fine product.