The VG´s are working incredible on my SONEX.
Because I have a private airstrip ( indeed it´s a little patch of green farmland) length 150 m , I could really feel the difference of "no-vortex" and "vortexed wing". I could get the the take-off distance down about 25 m. The climb-rate didn´t change, but the climbspeed is much better now.
Also the max speed is now in the average about 15 km/h more than before, at the same fuel consumption.
Sonex aircraft with 90 hp Subaru EA 81 custom made installation
cruise before 185 km/h now 200 km/h
stall speed 92 km/h 80 km/h
Take off distance 300 m 275 m
TO distance in my field 140 m 110 m
on my field (Uphill) 100 m 70 m
Climbrate is 650 ft/min
Result: Absolutely positive!