For many who come from a sport bike the change to a sit-up tourer or a travel-enduro represents a big change, and the screen / air-stream is a major reason. One thing before I start my two cents about screens: Whatever you will do, you will never get that kind of clean air-flow you had been us to!
Bascially it is about creating an air bubble, without causing too much draft and turbulences. For most people this is the case, if the screen's edge is just slightly below the line of sight, like 3 - 5 cm (1 - 2 inches). A barn door may lock out the wind even more, but usually creates a lot back draft. So, in principal you can use any screen and adjust / cut it accordingly. The rest of fine-tuning the air flow is done by finding the right screen angle for you. That is what I have done, here:
R 1200 GS/GSA : Individualized Windshield
From the ready made screens, the air flow receives a lot of good comments, see Stefan's contribution here:
R 1200 GS/GSA : Individualized Windshield . Else, what ghostrider said. Many people agree with his comments to the ADV screen.
And, before I forget it - welcome to our little GS forum! May I move your post under the windscreen section?