The risks for not wearing a helmet while cycling are high -- depending on your age, location and skill level, a naked noggin could land you anything from a hefty fine to an early grave.
I'm not paying $600 so I can look good, and seeing how they cost 20 times more than a typical bike helmet I have yet to see any proof that they're 20 times more effective.
They might have more success with a motorcycle version.
I'd trust an invisible helmet about as far as I'd trust an invisible head injury.
I'd trust the invisible helmet as much as I'd trust the invisible protective cup!