I'm no expert on Skydiving helmets but I was a biker for many years before getting into Skydiving. There was a widely held belief among many bikers that the cheaper polycarbonate helmets provided better protection in many accidents than the expensive Kevlar and fiberglass helmets. The theory was/is that the softer outer shell of the polycarbonate helmet partially coliapsed on impact, absorbing some of the force so less was transferred to the brain. The most credible source I heard this from was a motorcycle riding Paramedic who'd raced bikes and had been a sales rep for one of the well known (expensive) helmet manufacturers. ------------------------------------------------
We're a' just machines for makin' shite.