A good windshield is indispensable for over the road long rides.
Esepcially for those of us who live in No helmet law states who choose to ride without a lid. No bug hits at 70 plus miles an hour. (its amazing how hard a large bug feels on impact with your forehead)
The fatigue reduction on a long ride on the slab at 80 miles an hour is considerable.
And if you live in an area where riding year round is easy as it is here in Az but early morning commutes are still quite cold the windscreen does a good job of taking that icy cold blast and removing it from your chest , head and eyes.
I have an Alley Cat and although I am tall the slipstream is still an inch or two above the top of my head.