I am new to this website, but definitely not new to motorcycling. I have many hundreds of thousands of sport touring miles starting on my 1968 Bonneville.
I will keep my comments to the modern Sprints.
I have owned all three generations of Sprints. 96 Sprint, 98 Exec, 04 ST, and now 2012 GT. The total miles I have ridden on these 4 bikes is about 220,000 miles. The new GT is barely over 500 miles as it's not even 2 weeks old, yet.
I am 6' 3" tall. On the first three Sprints, helmet buffetting was a huge issue. In fact, it was horrible. I would move around on the seat, depending on winds, to avoid the area the buffetting occurred.
The only way to eliminate any buffetting was to stand up on the pegs. I did this a lot of the times on long, straight roads.
On the (2) 885 Sprints, I first tried a Rifle fairing. On both of them. That was like adding a barn door to the bike. Handling suffered as did fuel economy and even straight line performance.
The Rifle did work, but it came at too great of a price to everything else.
On the 04 ST, I had the best ride with the Zero Gravity. I first tried the optional windscreen made by Triumph. It sort of worked, but, I found this was also matching the barn door symdrom. I then cut 3 inches off the top. It was a tad ugly, but it did worked better.
The Zero Gravity was the best on the 04 ST. However, it did still cause some slight helmet buffetting. I tried three different helmets and they all buffetted.
The 04 ST is now owned by my son. He is 5' 10" and has no such buffetting. Therefore, as I suspected, the amount of helmet buffetting is rider dependant.
My GT is totally free of helmet buffetting. Also, the very aggrivating lower ear wind noise is quite reduced. I am using the stock windscreen on the GT.
I summize that Triumph went to some very good lengths when designing this windscreen. My body seems to be well protected from wnd. My head is stickup up in what I call "clean air". Clean air is MUCH easier to tour on than dirty, buffetting air.
To look at the stock GT screen, it looks worthless. But, it's a LOT different to ride behind it.
I would like to see a very indepth testing of the Zero Gravity fairings, if they happen. I also feel that wind discomforts effect each rider differently....J