Although everyone seems to be under the impression that helmets like the Bern provide more protection, I don't think that's the case. Yes, they wrap around the back of your head but that's not a place where bicyclist tend to get whacked when we crash because we usually don't fall backwards like skaters or skiers do. All of my impacts...and I've had several... have been towards the front of the helmet or just over the ear. I did 'go over the high side' in a crash once and smacked the back of my head but it wasn't that as low down as the back of the Bern goes.

As for multiple impacts, I take that with a large grain of salt. The helmets still work the same way, i.e. the expanded foam (EPS) in the helmet is meant to crush and slow down the head and brain to keep the brain from sloshing around inside the skull. But it only crushes once. After that it is compromised and it's effectiveness is severely limited.