Lots of posts here bashing this product while I bet exactly none of them have tried using one yet.
No argument Dyson makes a lot of high-dollar products that just attempt to be a little better/different than the norm -- and won't impress people who are always looking only for the lowest cost solution.
But I have yet to really use anything Dyson branded I thought was a bad/dysfunctional product. I owned the orange Dyson ball vacuum cleaner, many years ago, when it had only existed for a short time. It was 4x-5x more expensive than a typical Hoover or Eureka upright vacuum from a discount or department store. But I got a good 12-13 years or so of use out of it, before selling it to someone else. I remember when I first got it, thinking it felt "too plastic-y" with plastic hoses and attachments and levers. Wasn't confident it wouldn't just crack/break on me. But it never did, and my only real complaint with it was the ball design prevented getting the vacuum under the coffee table. (Obviously, switching to one of the suction attachments let you get around that.)
I feel like at $500, I don't want to be the first guy trying one of these out. But if early adopters decide it really works, and isn't too slow at sensing where gaps are between your teeth while brushing with it - I would consider buying one on sale and giving it a shot.