Well, how would you prove that? You'd have to have a significant body of crash results, large enough to mitigate differences in crash circumstances. I don't think anything short of a few thousand crashes in MIPS helmets would suffice statistically.

Given that they're pretty expensive, and people who buy them are probably pretty safety conscious already, it's likely that there haven't even BEEN several thousand serious crashes of people wearing MIPS helmets, let alone several thousands with proper reporting.

They HAVE incorporated a lot of research into what causes brain trauma, and they have used sensor packed dummy heads in simulated impacts.

I kind of need my brain, and for me $200 to increase the odds of not damaging it was not a hard decision.