Not decrying the benefits, but having looked at them I just can't see how the price can be justified. I wouldn't buy one for myself and not for everyone who was likely to be on the boat. So that would mean paying for five or six and that, for me, would be a significant outlay. It's getting on for the price I paid for my new 6hp aux and given the choice of one or the other my money would go on the aux.
I think if there were other manufacturers making them they would be more realistically priced, maybe £40 or £50 after all, they can't be costing any more that MC helmets to make and CE approved ones of those can be bought for less than £40.