Pick up a 7 or 8 inch LRS and you will see the difference.

Right now I have a borrowed SGS stock shield on my FLHTK, experimenting with air flow and vents on my new SHOEI GT-Air, the vent does way less than it does with either my 8" LRS Ultra Elite or my 10" LRS Ultra.

 

I am 5'6". The buffeting is minimal as I am short. I tried the vent in both positions and really could not feel a real difference. I would say taller riders benefit.

 

FYI; Harley is thinking about removing the on/off function from the fairing vent.I think they are finding that everyone leaves the fairing vent open, regardless of weather.

To your question, the vent works well on my 14 Limited. It might be the taller shield.

 

Ditto on what Safetyman had to say. at least on the windshield height part, I can't attest to the part about being dickie.

When the tour pack is off and I put a street glide windshield on I don't notice much of a difference. However with the limited windshield on, huge difference. My glasses don't shake and rattle. Cigarette ashes kind of float in the air right behind the fairing.

 

When you get your bike, check it at 40, 50, 60, 70 with the vent open and then closed.

Variables: height, seating position etc. I find a noticeable difference. And so i have always ridden with it open, rain might be an issue, but i try and haven't ridden in the rain.

 

I just bought a 2015 SG. Took it out on the highway and my sunglasses Did fall off. I still LOVE my SG!!!!

 

It works a little. I would rather have it than not. I have the 7" LRS and the fork fangs and I think it's perfect. The fangs made the biggest difference with my glasses shaking.

 

Its not fun with the vent open in the rain

 

It makes a big difference on mine. I ride with mine open all the time.

 

I think it makes a difference.