Pros: Airy unfatiguing treble, epic sound stage, brilliant mids, extensive and textured bass. VERY comfortable. Worth way more than what you pay.
Cons: Non-detachable cable? Can't think of much.
I'm just gonna start off by saying I love this headphone. It has dominated my head time since I got it. My HD650 gets no love anymore. They are just incredible. They're easily worth $400 in my opinion.
My first serious headphone buy (HD280 5 years ago not included), I got the 250ohm version and used it with an E17 for a month; I ended up returning them to Amazon due to getting the HD600 and HE-400, both of which I ended up selling and returning as well. I couldn't justify 2 pairs, let alone 3. I got the HD650 and it changed everything. I ended up selling/returning everything. Once I got the Lyr and Bifrost, it changed everything. So that leads us to early December 2012...
I had the money and decided to get myself a little sumpin sumpin if you know what I mean. I got offered a sweet deal on some great condition 880/600s and leaped at it. And here I sit, writing this ridiculous rave review about them.
What I love so much about them versus the HD650, which is great, is that they're exciting. The treble is sparkly and clear. There is a nice air to the music, something spacey to it. It's awesome. The HD650 is a bit more closed in and intimate. I listen to a lot of electronic music, so I expected to like the DT880s more. What I didn't know is how much more I would like them. Now, maybe I'm exaggerating... but they're the spice that my music needs! They make everything lively. With a little EQing, the bass is thumpier and wobblier. The best part is that the Lyr has an insane amount of head room, so they never clip or distort. It's just cerebral.
Versus the DT880/250s on the E17, the mids are much better and bass goes even lower. With the Lyr there's even more detail to the treble as well. I see now why almost everyone has the 600ohm model. It's just better in every way.
I can wear these for hours and my ears might get a little warm but only due to sitting inside earcups for 2 hours! They're light, sturdy and have just the right amount of clamp. In contrast, I think the HD650 is a bit tighter.
I think they're worth just as much as HD650s, because if you amp them right, they will reward you.
Source: MBP (optical}
DAC: Schiit Bifrost
Amp: Schiit Lyr
Tubes: 1972 Orange Amperex PQ (Holland)
Compared to the stock GE tubes with the Lyr, the DT880s are more revealing but warmer. Bass might be the tiniest bit less? But mids are even better. They sound almost just as good as my HD650.
Oh, and they work plugged into my iPad 4 @ ~80% volume. Perfect for movies and music. It's nothing special but it works!
-- TL;DR --
Basically to sum it up, the DT880/600s are some of the best headphones I've heard in my life, if not just due to my preferences. But their combination of detail retrieval, airy soundstage, incredible positioning, balanced but satisfying bass, and unfatiguing, sparkly treble is just...something to behold. It works well for almost everything, provided you have high quality source material.
Best value at this price point, in my opinion. Other close competitor is the HD600, which is great too, but emphasizes different things.
I love my DT880.