I think the key take-aways are: * any helmet provides significant protection vs. not wearing a helmet * there is no correlation between cost and protection le

I think the key take-aways are: * any helmet provides significant protection vs. not wearing a helmet * there is no correlation between cost and protection level * there may be a correlation between protection and rotational-focused technologies (i.e. MIPS et al) but it's hard to tell because most manufacturers don't have a non-MIPS product anymore (where they do I don't see both the MIPS and non-MIPS models here)