Got my C3 late last year and not too impressed with it.
I find it noisey and visor edges fogs around the pinlock which puts you off a bit whilst riding. I also find it stuffy and not even got into summer yet (or did we have it the other week?)
FYI, BMW do inserts for their helmets so you can get a better fit but these cost extra. However, you may be able to do a deal with the dealer. Wish i had tried a BMW on now.