Kolb Firestar ll
Purchased some of your VG's a few months back, got them installed last week. Stall speed dropped 5 mph indicated, handling just above the stall is very good, stalls are very gentle. Well satisfied.
The aircraft had previously been flying with home made VG's on it, and it is certainly much simpler to simply send you a credit card number and stick yours on. Performance is about the same, with about 20% less time and fiddling around, plus the bonus of not having to worry about slicing a finger when washing the wings...
Here is the web page with the before and after pictures, perhaps you can use it.