Bought the 10" after measuring as recommended. OEM was also 10". OEM had wind buffeting at top of my ears. F4 buffets at top of my head now. On gusty or windy days, at speeds under 55, the F4 catches the air and is a bit wiggly in the steeering because of it. The OEM does not do this. However, it speeds over 55 and up to well over maximum highway speeds, it's quiet. The wind does not increase with speed, nor is there any appreciable sound increase.
The biggest complaint I have is the contour of the shield where it mounts is not correct. It's not curved enough. It therefore pushes the outer fairing away from the inner fairing, and puts a lot of tension on the mounting bolts, that according to LAB's video can strip easily.
It's a nice windshield that is very stout and clear as glass.