Same situation as smokeeater.
My F4 has a small nick from something hitting it,but has no noticeable scratches.
Simple answer for me is.. the F4 is extremely scratch resistant as advertised.
Why try any other?
I have a V stream special and no noticeable scratches. it was on my bike ehen i got it so no idea how old it is. Coincidently i got my bike,now a trike, from National Cycle in Chicago, the manufacturer of the wind screen and wind wings, they are on it too.
Not sure of the V, but my F4+2 is over 8 years old, and other than a couple of rock chips, there are no scratches. I have cleaned it with every type of paper towels and rags, and have used different cleaning "stuff" and it still works great and looks great!
It isn't just the windshield that makes F4 the best choice for me.
It is the way they treat you with their direct customer service approach when you have questions or an issue.
That means as much to me as a scratch resistant windshield.