I have tried a few shields. For reference, I'm 6'1" and long in the torso. I have run an AngryStad for ~3-4 years on my F6b. Mine has the 15" outer shield (the size recommended on the manufacturer's site for my height). Whether fully up or down, I'm looking over it. Fully up, it creates a very, very still pocket around me. Fully down, it gives more air on hot days, but still quite buffet free, with the air reaching the top of my helmet and a nice breeze around the chin. I added linear actuators to mine so I can adjust it on the fly.

Prior to the AngryStad, I had the Honda Tall with vent (very turbulent and quite low for me) and a Clearview Full Wing +4" (i.e. 4 inches taller than a Full Wing factory shield) with vent that worked well, but it never quite matched the AngryStad for smooth airflow. That thing was a barn door.