There has been a ton of research I have put into both snowboard helmets and bicycle helmets. I have concluded for myself that they don't do much for speeds greater then about 20mph. Thanks for the stories I'm always glad to hear when people male it out of bad crashes. But the fact is in both stories it is just a guess that the helmet saved you and your dad.
Not really a park rat I just want something to eat up some of the energy from blunt trauma. When snowboarding and I feel the need I carry a mouth guard which I feel is more effective at preventing concussions .