Hi there,
I've got the Givi smoked windscreen, bought it a month ago and what a change, should have bought it 3 years ago...
When you ride the bike in cruising position you can go up to 160km/h without much wind (I'm 1.82m tall). When cruising at something about 120/130km/h you are virtually wind free.
I've ridden up to 195km/h in an upright position and you can really feel the difference.
The design is adequate to the bike, it has to be very tight with the headlight protection. Otherwise you'll have a painfull rattle every bump you pass. Other than that, it's a perfect mod.