To start with, readers of this review must realize that the 250-ohm version of these phones was designed by beyerdynamic to be used with a fairly powerful home audio system. The 32-ohm version was designed to be a better match for the iPod/laptop crowd... of which I am not a member.For me, the reason for this purchase was rather specific: I have a moderately high-end 5.1 home theater setup (Yamaha / Klipsch / Philips / Toshiba / 58" Samsung Hi-Def Plasma), and for quite a while now, I've been looking for a way to watch DVDs and listen to CDs late at night, without disturbing my neighbors (I live in a fairly upscale 55+ mobile home park)... but also without losing the incredibly accurate sound fidelity to which I have become deeply and happily accustomed.Finally -- having read almost every online review that exists of the 880's and their chief competitors -- based on my listening tastes, I decided on the 880 Premiums.Upon first listening to them, I will admit that they seemed to be very slightly treble-heavy -- and a bit light on the bass end. Even so... without any break-in at all, I thought they sounded REALLY amazing -- very clear and clean -- and initially, I honestly could not have been more surprised and pleased.That was two weeks ago. Since then -- while I've listened to a number of CDs and watched several DVDs -- in order to more rapidly burn them in, I've been playing CDs through them almost around-the-clock, with them mounted on a foam cushion, instead of my head. As of this evening, they have accumulated just over 200 hours of use, so I consider the burn-in to have reached completion, and -- as I'd hoped -- the further into the burn-in process the 880's have gone, the more even, smooth and true they've ended up sounding. So, amazingly, what started out as being phenomenally good -- to my ears, at least -- has gotten INFINITELY better!While my DVD collection includes every type of film imaginable, my CDs and music-concert DVDs are primarily jazz and classical. Last night, I watched Pat Metheny's "Speaking of Now: Live" DVD, and even though the spacial representation of DTS 5.1 is lost, the accuracy of sound reproduction through the 880's was flawless, and their sound stage is open enough that I never felt as though I wasn't "in" the film. I also found this to be true while watching my Blu-Ray of "Avatar" the night before; COMPLETELY realistic.Tonight, I watched my Blu-Ray of "Jeff Beck - performing this week... live at Ronnie Scott's", featuring the 20-something phenom Tal Wilkenfeld on electric bass. Let me just say... while many reviewers seem to feel that the 880's bass response is somewhat lacking, I personally am ASTOUNDED at their ability to so clearly define, express, and reproduce every nuance of intonation and touch in the playing (for instance) of acoustic standup bass... right down to the lowest notes of which the instrument is capable. At the same time, neither deep electric bass notes nor loud, low drumtones are ever the least bit harsh, distorted, or uncomfortable in any way... yet they are fully, perfectly, and accurately THERE. Pure pleasure!And while the 880's certainly can't reproduce the (literally) earth-shaking Low Frequency Effects of which my 12-inch Klipsch sub-woofer is capable, the very-low-frequency response of these phones, in the midst of explosive, calamitous film action, is FAR beyond my expectations. Several times now, in fact, in the middle of some on-screen battle or disaster scene, I honestly have spontaneously taken the 880's off my ears, just to make sure that my sound system really was NOT on!Final evaluation: WOW. I absolutely LOVE them!Update, December 13, 2012:By way of reinforcing my conclusions, as represented in the above review, I'd like to add that, over the past eighteen months, I have become so enthralled with the accuracy of sound reproduction of the 880 Premiums, and with how incredibly comfortable they are (again -- so as not to disturb my neighbors late at night -- I often wear them for four or five hours at a time), that I bought a second pair of them a few weeks ago, so that a visiting friend can enjoy a (sometimes exceedingly loud) late-evening film or CD with me.And what's truly nice about that, is that even though we're both wearing headphones, it remains a genuinely "shared" experience... which would not be possible if we were wearing "closed" headphones. Because of the "semi-open" design of the 880s, we are still able to make comments to each other during the film, or carry on normal conversation, without having to remove our headphones or pause the film or CD -- just as we would if we weren't wearing headphones at all.Allow me to repeat myself: W-O-W. I absolutely LOVE these things!