I've had this for about a week and have really mixed feelings. The resolution, speed, soundstage, and separation are top notch. However, the tuning is really weird. Supposedly "flat" but actually equals a big mountain of upper midrange, light bass, and rolled off treble. It seems that Audeze wanted to make a very midrange elevated headphone for studio users, and relying on home listeners to use drastic EQ correction to get a pleasing sound. Of course, if you have an actual reference head-fi system, going back to computer playback and DSP EQ is two steps back. I'm really concerned that they aren't tuning the frequency response of their headphones to sound good OTB and just assume you will use mid-fi DSP plugins from a laptop.
Beyond that, I used to work in pro audio and I'm still not sold on the utility of having this much midrange boost in a studio headphone. All the music I've listened to this sounded very unbalanced. I never mixed music on studio monitors or headphones to sound this vocal and guitar exaggerated. Really wish they could have created a reference level phone with a typical/pleasant Audeze tuning. If this had the default FR of an LCD-X it would probably the absolute best planar headphone out there. If someone wants an unflattering mid-boosted sound, let them EQ that in.