I have not heard this headphone, so I don't have much of a response as of yet. There have been a few impressions on Head-Fi, which you should be able to find if you search for 'Chocolate Donuts'.
I bought it based on swt61's description as I trust his ears and preferences. In his opinion they are on K340 level, though different in many ways. With the YH-100 drivers he believes them to be far superior, approaching and maybe eclipsing the Stax Omega 2.
Now, assuming Steve has the same opinion of the K340 as I, that would place them a little above balanced HD650's to my taste. I don't much care for the Stax Omega 2 myself, so that comparison doesn't really help me.
I got a great deal on them and have been wanting to dive into orthodynamics for some time, so I am very excited to hear them. If I can manage to track down a pair of YH-100 drivers, even better.