Less than a week with the C3 and thus far it's been an awesome helmet. Then again I went directly from a way less expensive helmet: KBC (with Interphone F4) to the C3 with the SRC, so my baseline expectations going in are relatively low. The SRC is flat out superior in every respect to the F4. The noise level, comfort and just plain coolness/convenience of the integrated sun visor makes this one of my most satisfying gear purchases ever.
Last night I rode through a moderately heavy rain for ~30 minutes and did notice the glare from oncoming lights I attribute this as much or more to the rain and the fact that I wear prescription eyeglasses.
I too have to give a good two-handed push on the flip-up to ensure the helmet latches properly, I think the SRC collar plays a factor and that the effort required will lessen over time as the helmet becomes broken-in.