I purchased a -2" F4 with no vent for my 2003 Wing. Oct 2016 with Over 5 years and around 75,000 with it I purchased another Wing (2008 with 16,000) and it had a stock windshield w/vent in good shape. I don't like the stock shield w/vent being it's taller and not a real fan of the vent either so t swapped the shields on my 03 to the 08. I've since put another 14,000 miles on the 08 Wing with the -2" F4. So far about 90,000 miles and 6 years and thus F4 is still in very good shape and still repels water just like when new, no swirl marks on shield (no scratches either) and no Halo's around headlights from oncoming traffic. I used to not ride when it rained because rain beads up and doesn't shed well on other shields I've tried but this F4 sheds water like a windshield treated with Rain-X. Now when it rains I simply raise the -2" F4 to full up and keep on going. I also have the full Monty Baker Air Wings installed on my Wings(a must have) and just came back from the full Eclipse show down in Booneville, MO (only about 200 miles from home) and after leaving to head home it started raining and at times pretty hard. I didn't even stop to put on my rain suit which I rarely ever use now days. I had on jeans, t-shirt and leather vest. Stopped for gas in Princeton, MO for gas under an awning while still raining and didn't even bother to put on a jacket then and finished my trip home. I stayed dry too by the way and the outside of my shirt sleeves were only damping.
I will not own a bike without one of these awesome F4 windshields on it.
ps. About 4 years ago a Falcon chasing/preying after another bird flew from left to right across my path at highway speed of about 65 mph and impacted just right of center on my F4 Deflecting in to my right side mirror. Not a single mark or scar to shield or bike. All I had to do was put the break away mirror back into position. The Falcon wasn't so lucky though.
Highly Recommended product and very satisfied customer.