Functional for what? I agree, markymcd, if you're going to sp end all your riding time on the Interstate, then those Popemobile screens might get you into a dome of silence. But if you're going to spend any time at all off pavement (and if you're not, why on earth would you buy an F800/650GS?), then those big screens are just an excellent opportunity to get your larynx severed every time you go over a whoop. DAMHIK.
Me? I'm sticking with the stock screen and a good pair of ear plugs.
__________________ Frank Reinbold "Every bike I ever had, was the best bike I ever had, when I had it"