I received my UE6000 yesterday and I have to say that I am quite impressed by them, both with and without noise cancellation. I feel that the noise cancellation makes them a bit more V shaped, which of course, by my sonic preferences isn't necesssarily a bad thing at all. The bass is punchy and goes deeeeeep, the mdis are rather lush and the treble is unintrusive when noise cancellation is off and a bit more sparkly when noise cancellation is on. The sound is definitely a sort off "attacky" type of sound as opposed to laidback when noise cancellation is on, which probably isn't a good thing when trying to chill out, but much more so when trying to work and get up a good pace. Soundstage seems open and not too big, which I can sometimes feel about the D2000's.
I guess I would describe these more as portables rather than stationary-at-home listening devices, however, as with almost every closed headphone that isn't the size of Denons old D-series, these will work well for both applications. Comfort wise I have nothing to remark on, except that the (p?)leather pads are quite sturdy and hard as opposed to softer pads. These are probably on the heavy side of things, but truth be told, I don't notice it while wearing them. Maybe my neck muscles are stronger than I have given them credit for.
Overall I'd rate these as somewhere between the D2000 and the M50s. What I mean by that is that I probably like the D2000 more, and the M50s a bit less, but seeing as I really like the M50s this is clearly an above average grade from me. I definitely like these better than my HD25-1 II, however, the HD25-1 II probably handles faster rock better. I'd also rate these higher than the Pro 900, but to be honest, it's been a while now since I sold them so I don't necessarily recall their sound correctly anymore, thus I should probably leave them out of future comparisons. These are also better than my HP-800's I think.
I think these will be my new synthpop/techno/EDM/house headphones. The bass is not strong enough to make these my hiphop/trap phones, that title is still held by my XB's, by a huge margin. I thought of leaving these at work, but no, I like them too much, and my HP-800's will remain my work headphones. That isn't to say that I won't be lugging these to and from work at times, especially now that they're new, but they won't stay here like the HP-800's will.