I installed some of the Nippy Norman's winglets over the recent bank holiday weekend and they make quite a difference for what is such a small, simple piece of kit.
Some words of warning: on my F800GS, there's a load of electrical gubbins under the left hand fairing just where you drill the rear-most hole. Thankfully I noticed this before I started drilling, but I found it easier to loosen the fairing panel and pull it away to avoid FUBARing the electrics!
What's so bad about a bit of wind blast? Keeps you awake on the boring Motorway miles.
I'm yet to find a tall screen that's aesthetically pleasing enough to warrant putting it on my bike, to me they all look like 70's rickman fairings. The styling of the F800GS is all sharp points and angles which is incongruous with big floppy rounded touring screens that are available.
I've ridden through the last two winters, including a rather unwise 280 mile ride through last December's epic (for UK standards) snowfall. I find my hands and feet are the things that go first not my head