I am soon celebrating my 50th birthday and received an Arai Defiant Helmet as a birthday gift. I thought I would post up a mini review of the helmet after the first 200 miles. My previous helmet was an Arai RXQ and the one before was an Arai Astral X. Guess I just have an Arai head. In all I wear an XL and the fit is very similar but the Defiant is a little larger. I am ordering a set of larger cheek pads which should take care of it for me. As for venting the helmet flows alot of air. Much more than the RXQ and approaching my old Astral X. So much so, I thought of closing the vents on this mornings ride which started out in the 70s. This is a big deal deal for me as I wanted a helmet that vented really well. It seems Arai has altered the vents to work better on a standard bike and thus far that seems to be the case. My Sena SMH-10r fit well with no real issues even without dedicated pockets for the speakers. Really wish Arai would copy Shoei on this detail. I will post up some more thoughts as I put more time with the helmet.