At least I do use all of that to properly clean every area and if they do it simultaneously to regular 2min+ brushing, I'm interested to see how that works in terms of water usage. Likely why they got the camera, for short bursts, looking forward to read some papers on how well that truly works vs a consistent stream.
Besides that, I personally always liked the totally round, smaller Oral-B heads vs Philips and other electrical toothbrushes, mainly cause that's what I grew up on. Seems Dyson is somewhere in the middle, smaller than most but not quite fully round.
Price as mentioned is a lot, but not unprecedented for those just buying the iO Series 10 or Philips equivalent + an Aqua flosser. Though there is no real reason to go for the 10, e.g. 8n is identical even in the superfluous comfort features at often less than 50%.