I finally got around to doing the installation on my KIS4 Cruiser elevator. I have not taken any actual hard data but I can tell you they made a BIG difference on how the airplane handles and feels. I have much more elevator authority and can keep the nose in a higher attitude than before maintaining a much slower approach speed all the way to touchdown. The big indicator for me is that once the mains touch down I can keep the nose wheel off the runway for about 500ft, something I could NOT do before installing your VGs.
I am very pleased with the results as of now. I should have installed these VGs a LONG time ago. :o)