Trust me, I tried! I tried a power bronze touring windscreen. It takes a tiny bit of wind off of your torso, but just directs it all right to your head.
I had a 2006 919. It's one of the most beautiful bikes ever built. I love the naked feel.I could ride this thing all day at freeway speeds. I'm a purest.I don't need all the bells and whistles.
The standout thing about the 'bird is the smoothness and effortless way in which it rolls along. Yes, it's heavier and longer than a supersport but with some effort it can scratch through the curves very well. My suggestion would be to keep both bikes. Use the Hornet in the warmer months.