For sure the shape of the windshield is very important, however it is also very important to know :
- where the edge of the windshield is located according to your face ( eyes, nose, mouth, lower ... ) ?
- how far your face is from the edge of the windshield ( closer the better but difficult with a road glide ) ?
- which kind of helmet do you wear (if you are wearing any ?). Having half a dozen of helmets at home, I know the ones I will not wear for a long ride !
However enjoy the ride with a good piece of wind on your face and you will have a good sleep at night !