I recently installed the CalSci 20" windscreen on my GS8 and went for on a nine-hundred mile trip. AMAZING. Absolutely leaps and bounds better than the OEM BMW screen. I'm 6'1 with a 32" inseam and the air stream hit the top of my helmet providing some much welcomed air flow, perfect. I have the screen adjusted to its most "laid back" position. Wind noise was cut down dramatically. I now listen to tunes at 2/3rds volume from my iTouch, instead of 95%. All in all, a great purchase. Well worth the two-hundred bucks!
I ordered bar risers today. So, adjustments may have to be made. Maybe move the screen to the "middle" position, since I will be sitting taller. I'll keep you posted.