Just mounted a Spitfire Slip Stream on my DR. Handlebar mount. Height Is 19 inches from center of headlight cowl to top of screen. I'm 5'10" tall with a 32" inseam. Use some kind of spacer between the screen and number plate, at the bottom, so the screen doesn't seal to the number plate. This will prevent turbulance. Very little pressure below 50 mph, between 50-70mph air pressure about the shoulders is about the same as without the screen. From 70-90mph the pressure stabilized and did not appear to increase with speed above 70mph. Without the screen, the faster you go the more it trys to drag you off the bike, as you know.
No change in handling or fuel mileage.