An in depth Japanese review is out on YouTube, i've been translating the comments to the video (the video reviewer replied to most user comments) and the reviewer is basically saying it does not compete in the $200 to $300 range and feels like a wireless headphone meant for audiophiles.
Some weird translation oddities so can't be completely sure, but it sounds really positive. Lots of Japanese commenters saying they're going to buy them after his video.
Will be interesting to see English reviews. I would guess most mainstream reviewers will say it's too expensive and doesn't sound much better than cheaper options, but I am more interested to read reviews from professionals and headphone enthusiasts. I would imagine a lot of casual tech reviewers who are not audio enthusiasts can not tell much difference, or if they can, simply don't care enough to justify the price.