I had posted this on session involving windshields.
So...here it is again
Started with the summer screen. Then the roadster screen. Then a thing called a lip. The bike wasn't worth owning for two years. Triumph factory folks were clueless at best. The dealer told me to put paper towels in my helmet. **** fool! The only fix to the buffering is the lower reflectors. I bought the taller Clearview and had the same problem. Bought the lowers and I thought I had a new bike. Can light a match at 80MPH. Bang! Hit a deer last year and ruined the windshield...among other bike and human parts. So I decided to buy the shield with the cutouts. It's now sitting in the garage if anyone wants it. I didn't have the lights installed yet but the air flow from the cutouts caused buffeting again. So, I bought the full clearview shield with the vent. It's perfect. It's so much cooler in the summer with the vent open that it's unbelievable. The vent is a must. The only down side was I hit a bird this summer and the darn thing hit right on the vent. Strained the feathered fellow all over me! Parts hit the exhaust ands it smelled like a BBQ for a week.
The Triumph lowers are a great help. Although, summer heat can be an issue.
I've the Roadster screen. There was a tremendous reduction of helmet buffeting after adding the lowers. I wear a full face helmet. In the summer heat (95+) the absence of flow reduced by the lowers might be an issue for you as well.
There is a design issue with the OEM lowers. It has been discussed on occasion. In my case there was, after closer inspection, impact upon the chrome radiator surround at lock to lock positioning. Flip came to a derived a solution.