Both screens sit at about the same height, although the Prima may be just a bit taller. I'm 5' 10" and get a tiny bit of face wind from the Cuppini but not with the Prima. The Cuppini is considerably narrower, especially at the top as it tapers. When riding my naked scooter back to back with my wife's and the Prima, it was night and day. The screen makes for a much less windy ride and I was finding that my eyes were watering, especially in cooler weather.
The Prima's extra width does offer more wind protection and I don't notice any more hand protection with the Cuppini, even though it drops down on each side of the headlamp.
The Cuppini hardware separates the mirror stalk from the screen mount, and in doing so pushes the mirrors up and out an inch or two. I find the mirror placement superior with the Cuppini with much improved visibility. That said, I imagine it would be possible to get a bit of extra hardware and do something similar with the Prima. Installation of the Cuppini was easy, with the instructions available at Scooterworks. It took about 10 minutes of fiddling with fine adjustments to get the screen lined up properly and the mirrors where I wanted them.
The Prima is a bit like a Plexiglass Pringles potato chip, offering a good deal more coverage. Installation was also easy on it and it was less fussy with fine adjustments.
All in all I'm happy with the performance of both screens. The Prima is a bit less money, offers more protection and looks fine. The Cuppini has a more stylized look, offers good protection and comes with better mirror mounting hardware. The Prima might get a slight edge over the Cuppini mostly due to price and protection but I'm delighted with the Cuppini and it was exactly what I was looking for on my black Buddy. Wife loves her Prima and hated riding my naked Buddy. You can't go wrong with either.
