I bought a C-3 shortly after they came out, and before they were, umm... legal in the US (on an internet sale from the UK). It's a nice, light, comfortable, and rather well ventilated helmet. The built-in sunshade is a nice addition. If I have a gripe it's riding poorly lit roads at night, the double layer (fog free) visor gives me ghost images of oncoming headlights. It's not so noticeable on well lit roads, but the first ride in the dark-dark (every year) is a little unnerving.
Must be a BMW thing... the only Schuberth's I've ever seen on the road are on Beemer pilots. What's new on the "pro"?
-Mike