I thought I would post some initial impressions of the DT880 Pro (250ohm) for others to compare/contrast with the 600ohm. I've most recently been using Grado SR80i's so technically the Beyers are the highest end headphones I've heard so far.
These are supposedly tighter clamping than the non pro versions but I find them just about perfect in this regard. Any looser and they wouldn't feel secure (I have a small head), I could probably do some mild head banging without worry. Earpads are very comfortable, even a little big for my ears, plenty of room. Easy to use while wearing glasses. I like the coiled cord.
Worst case scenario for sound, directly out of my Samsung Epic 4G (rooted, custom ROM with voodoo sound mod, Wolfson DAC) They are overall cleaner and smoother sounding than my Grado as well as more balanced. I think I hear a slight emphasis or tonal balance leaning to somewhere in the upper mids with a slightly bleached maybe or chalky or almost grainy haze over the sound like a shhhhh type of sound, hard to explain. Very mild, just enough for my brain to say it is not that black velvety or liquid type of background you would expect from perfect reference. Might be more obvious if I ABed next to a high end reference system. Not really noticeable if I power them from the headphone outs on the cheap computer speakers so I assume it's mostly an amplification issue. Generally I feel a desire for just a little more emphasis in the very low bass, though midbass sounds fine. Overall is very good though I feel they should be capable of a bit more definition of notes, more so on the low end and slightly better dynamics but hard to tell as I don't have the best reference recordings to test them. I expect things to improve slightly with better amplification but overall really have nothing to complain about as far as the general sound goes. They sound fantastic. Probably pick up an Objective2 in a few weeks.
Joshua

Edited by AzraelDarkangel - 2/6/12 at 12:55pm