Have most of these helmets been thoroughly test to actually prevent injuries? The reason I ask is, there are a lot out there so which are good? I'm sure some are better than others. This is the same with car seats for kids. A lot to choose from and some do next to nothing to prevent injuries and are faulty.
I'm not saying child car seats are useless, nor am I saying the same for helmets but if you're barreling down a run at 50mph and wipe out and bang your head, how much will a helmet help you? I've been in the market to buy a good one and I'm surprised how light they feel with don't have a whole lot of padding.
If you get a ski race helmet I bet those are rated for speeds above 50...