There have been so many threads lately about 'plastidiping' shit, just don't mess with your helmet, okay, so not worth it!
As for the legitimacy of wearing one, I did some more digging. To my understanding, when the impact is with soft snow, helmets offer no extra protection as the potential for injury is low. When the impact is with a stationary object such as a rail, a post, or a tree, helmets can greatly reduce and absorb the force of the impact. Now, helmets are extremely effective at preventing minor injuries such as lacerations, but offer less protection from serious head injuries (brain trauma, concussion), especially when the impact is with a stationary object (again). They will decrease the impact, but often even the decreased level is so high trauma still occurs. Helmets are only rated up to a certain speed/force of impact, one that is scarily low for the real world use in freeskiing. As well, this impact is only tested on a straight vertical impact, something you'd rarely find in skiing.
http://skicanadamag.com/2011/12/05/gear/helmet-science
http://www.wildsnow.com/4713/ski-helmets-backcountry/
IMO i'm still gonna wear one, but no doubt helmets will not PREVENT sever concussions or traumatic brain injuries. What they can do is lower the speed/force of the impact, hopefully to a more reasonable level.
