Check out this website.
I had their medium sized windshield and their mini fairing on my R1200GS and it was BY FAR the best Farkle I have ever had. It totally changed the airflow around the bike. I could now ride at any speed with my visor fully open and no longer needed earplugs at all.
It was great.
BTW...I am 5' 9" with a 30" leg and I had the seat in the lowest position. The Medium sized windshield was exactly right.