Some early, early impressions, using my new Audio-gd C2C amp that is also burning in, so take them with a grain of salt. Overall though, I am very pleased with these so far, and I feel that they will make a good complement to my DX-1000's.
The phones themselves:
-A bit smaller than they look in pictures
-Also, a bit heavier than you anticipate
-Very comfortable, no headpadding problems like with the DX1000
The sound:
-Amazing transient response, lots of air around notes
-Huge, very wide soundstage, very similar to the DX1000, but perhaps even larger. Definitely larger than the HD650, at least from my memory.
-Good bass response. Not as deep or hard-hitting as the DX1000 or HD650, but definitely more accurate, and very balanced with respect to the rest of the spectrum. Better than the K701 from my memory, so no problems there (I hated the anemic bass of the K701).
-Extended treble compared to the DX1000/HD650 but no hint of sibilance
-Very neutral, but not to the point of boredom. Certainly more neutral than the HD650's or DX1000's. Still very euphonic when paired with a warmer amp such as the C2C. I suspect that amp choice will play a big part in one's enjoyment of these.