My helmet visor gets wet, because I keep the MStad angled towards me so I clearly see over it. Other than that, only my lap gets wet from rainwater dripping down from helmet. Tilted straight up, only the top of my helmet gets wet.
I am not sure how this compares to other windscreens, but on my VStars with big 21" Memphis Shades screens, I would significantly wetter...however, that may have to do with lack of coverage on the bike itself more than the windshield.