Motorcycle Consumer News has been on Snell's bad list since they published (and still stick by) a report that shows the penetration resistance standard that Snell requires (which is what separates them from DOT standard) causes more injury than a "softer" helmet that gives and thus more efficiently absorbs energy.
I've seen the discussion in other magazines also. I think it makes sense. There is far more chance of impact with solid surfaces than there is with pointy things.
