Really good price. I ordered before the price drop, cancelled and put it back in.
After looking through numerous reviews, this sounds like (pun intended) the go to entry level planar magnetic headphone.
HE400i is $20 usd more, but from what I gather people the HE4XX is favoured over it.
Lots of reviewers were "meh" with the HE5XX, but seemed to like the Sundara if we are talking about the next step up.
EDIT: expected to ship December 4th