I'm happy with my Givi windshield. I also added Saeng microswirl edging to the top to give the wind blast a couple of inches more kick upward.
Saeng also make some pretty sophisticated [ and expensive] wings and mirrors for a touring windshield.
Since I use an open faced helmet with a shield, the wind thing was not really a problem...instead, I was trying to see if moving the airstream upward would lessen the wind noise at 40+mph. This may have been the wrong approach, so I stopped with the windshield and the edging. I use Plexus cleaner for all clear plastic, by the bye.
The noise problem has really been irritating, and I've gone through several good earplug types in dealing with it. This season, I've ordered custom maximum earmolds taken from impressions of my ears. I'm hoping that this lowers the wind noise so that it is not as much of a distraction, and a long term danger to hearing.