I know Ultrasones (generally speaking) are meant to be burned in for an insane amount of time (I've heard as long as 500 hours. That seems a tad excessive, but who knows?).
Nonetheless, I feel the need to share some first impressions about these relatively unspoken-of cans.
I'll start with a superficial but important note: When I opened the box I was greeted by the wonderful smell of... nothing. These headphones do not smell like rubber or plastic or fake leather or anything horrible. Which is nice, because the Monster Turbines IEMs I returned just before buying these smelled absolutely noxious.
On the physical, these are very nice looking. The lighting on the main photos of them online make them appear a bit more white than grey; they're grey with black. Still, they have a slick but professional look. The shiny branding on the outside of the cups is fancy, and the overall build quality is incredibly solid. I changed the sizes, folded them up, turned them, bent them, and they did not at all feel flimsy or poorly made. Do they seem indestructible? No. But I won't really worry too much about them getting damaged.
The box contains the hard carrying case (absolutely massive, though the cans themselves are rather large so it's understandable) with the headphones, two cords, and an extra set of pads. Both cords are extremely thick and sturdy, though I'm only using the shorter 1/8 inch plug cord as I don't listen with an amp or a device that has a 1/4 inch jack.
The sound quality is incredible. On my computer, running high quality downloads, they sound amazing. Deep, solid, yet not overpowering bass with strong highs and mids. Good balance, smooth with a large soundstage. They do not keep the sound locked inside of my head, which is a good thing with closed-back headphones.
Sound quality is a step down when they're plugged into my music player (my HTC Smartphone with the Rhapsody App and 256 KBPS downloads). However, a few adjustments on the Equalizer app and sound quality surpasses their performance with the computer. Full, wide sound with great but balanced bass.
Obviously these have no burn in yet (I've listened/let them play music for about 3 hours total). I'm sure overall performance will continue to improve, which is why I'll wait a while before actually reviewing them in full. I'm just enjoying them so much I had to share some initial thoughts. I can't believe how little mention these or their DJ1 Pro counterparts (same headphones, different coloring and labels) get on Head-Fi. I'm sure these can't really compare to the PRO 750 or legendary PRO 900. Nonetheless, for me (essentially a complete newcomer to the higher-end audio world) these are above and beyond anything I've ever heard before.