I've owned water jets, the ones I've had suck. I always end up going back to dental floss. These days string on a plastic holder which I hate because it feels so wasteful to have all that single use plastic, but they are just so effective and I hate the manual wrapping of string, so I accept the wastefulness reluctantly.
This product potentially hits home with what I'd want from an effective waterjet, and it also comes with a brush on top.
The price is high, that's for sure, but I'm guessing they aren't aiming at the average electric tooth brush market, more like a competitor to the oral b io series 9 segment. And sure they are quite a bit above that price point, but they got a lot more of a solution backing the price.