And in a report this past May the Snell Foundation, testing helmets and writing standards since 1957, found "no significant improvement in the MIPS helmet's performance over the non-MIPS model."

The difference is the "test". Various testing labs have created their own test protocols & methods that they feel analog real world accidents.

It'd be sweet if there were an easy answer for all the world's cyclists. For the affluent cycling enthusiast, just get yourself a 6D ATB-1T EVO.