I have owned a C3 since December 2008 - purhased at NEC bike show with a significant discount from the RRP. However, whilst I like the helmet overall, I do not think it is worth the money. As noted in earlier posts, the bloody visor auto closing over 35mph is very annoying, and there is water ingress in medium to heavy rain via the top/sides of visor even when fully closed.
Apparently, Schuberth have identified a manufacturing issue with the visor related to the mounting resulting in the auto closure issue - something to do with the tolerances on a machine not being correct or something, and the replacement visors from now "should" correct this feature.
I am currently awaiting said replacement visor from Oxford Products (UK distributor for Schuberth) for this problem - not bad given I have been chasing this since circa Jan/Feb 2009.

To be clear, Oxford Products have been responsive, but I feel Schuberth have not (totally blanking my attempts to email them directly for example).
To close, I would not buy Schuberth again....