Like edmKC, I too have the Madstad. I'm the same height as you and had buffeting issues with the stock screen on my black 2004 Wing (Nice bike by the way!!). I tried the MadStad - took me a while to get it set right, but now I have no buffeting even at 90 mph (about 140 kmh). Good luck and I hope you find what works best for you. Always nice to ride without that annoying buffeting!Welcome to the forum. As captain78 says above, play with the vent and you should be able to get rid of the air hitting the back of your helmet. I'm on my 4th windshield now, and I think I've now found what works for me - a Madstad. I tried a Windbender, which was good but didn't seem to do anything for my wife. Then I tried a tall F4+4 which honestly is a very nice windshield and creates a nice big calm'ish air bubble to live in, but I never totally got used to looking through. After a long ride a couple years ago in a bad rain and not being able to see through the windshield much of the time I vowed to try something different. My brother had installed a Madstad a couple of years earlier and was very happy with it, so I went with that, and glad I did. Not cheap, but very effective.
Do some fiddling with height and the vent and if still not satisfied, start reading reviews before you choose. Good luck!