So just installed the National Cycle F16 Tour Windscreen, and while it's not perfect, I must say I'm impressed by the diversion of chest pressure, and really the greatest difference at 70 to 80+ is the even flow of wind. Buffetting is much reduced because it's focused, and riding pressure in the gale winds of Texas much ameliorated by the windscreen. And it looks pretty cool, too, as evidenced by the number of people catching me in multiple parking lots to talk about the bike. No offence to totally naked, but a little bit of tinted accent goes a long way. I may change my mind and take it off when the weather warms up, but right now it's pretty much appreciated.
And while I had some challenges with the brackets, I got all to work, and still have significant degrees of adjustment.