FWIW, I've only used their road models, but I swear by Lazer helmets.

They look great (relatively, for you know....a styrofoam head-shaped bowl), breath well and they fit nicely.

I have a huge head/thick hair. Even most L/XL helmets don't fit well, but lazer has a XL/XXL offering that's perfect.

Also, I feel like I should say I have no affiliation with Lazer, other than a customer.