I am a beta tester for these. They arrived today and I have listened for a short while. Right out of the box they sounded good to great and seem to be opening up and sounding even better very quickly. I haven't been this stoked about an audio product since the Intuitive Design Summit loudspeakers.
Briefly, TO MY EARS: these are astoundingly detailed yet smooth, and they have great bass. My preliminary impression is that they must have more sonic RESOLUTION than other high end headphones (however, I haven't heard the Abyss, the Beyerdynamic T1s, or the Oppo PM-1s....). They're balanced tonally and have wonderful midrange. Vocals are stunningly lifelike, even before any significant burn in. No readily discernible weaknesses at this point--NONE.