It seems a small gap in between the headlight and the screen, plus a little more leaning helps the GS screens to be quieter. Adjusting this in a wider range than with factory adjustment mechanism is what both products allow you to do. So they do basically the same.
Without and with Tobinator

The difference - as you probably know already - the Wunderlich Screensave Vario allows for 20 mm adjustment only, the Tobinator for 65 mm. With 65 mm mm you have of course more options available to suit your particular screen and taste, you can tilt your screen right down to ridiculous angles.
Wunderlich Screesave Vario
Tobinator
I am using the Wunderlich Screensave Vario. May be 5 mm more would be perfect. But honest I would not really need my screen to be tilted any more, than the Wunderlich part allows. Beside of strange looks it would also make the screen colliding with the mirror stems or the handguards. See more pics here:
R 1200 GS/GSA : Individualized Windshield .
The second major point for both items is stabilizing the windshield. The factory holders are underperforming plastic items. They leave a lot play, therefore allowing excessive screen flutter. Probably this is better with the ADV's screen, since it has an extra bracket. I'd still think the more solid mounting with the Wunderlich or Tobinator is welcome.
OEM