I've had the 800/600ohm for a few weeks now and recently came from the HD600, the Q701, the K702.65 on my way to the 880s.
(in my profile you can see what I've heard in the last 6 months).
First off, the 880s are my favourite of this bunch mentioned. I would say, however, that both the HD600 and the Q701 both do something better than the 880s but their weaknesses prove the 880s to be a better performer all 'round. (I hated the K702.65s though).
The Q701s are very clear and have a great soundstage but their brilliance is limited to somewhere in the mids to upper mids. The bass is an approximation at best. You can hear the notes but they are weak and lacking body and definition. The HD600s also have a wonderful clarity but have a fatal flaw in the lower mids(?), a smearing and lack of detail that killed them for me. I even noticed this "flaw" in the HD800 so I don't know what that's all about.
The 880s to me are the best all around in comparison. Nicely detailed with very good bass that even has some nice rumbling visceral response that neither those other two had. For your music choices mentioned, I would definitely pick the 880s over the Q701s, particularly for the bass in the electronic music.
The Q701s are very nice for smaller chamber pieces and baroque music.
My only complaint about the 880s is that they suffer a little congestion. It's something I heard in the T1s as compared to the HD800s as well. It's difficult to explain unless you go from a T1 to an HD800 or Stax. The scale of the HD800 is a real "wow" moment. And if you've ever heard stax, there is an endless air to them that nothing seems to match.
The 880s don't have this. (nor should you expect that from something at this price) They can seem a little closed in, while at the same time seemingly to have a good soundstage. BUT... it's only one of those things that you notice if you've come from something that is more open. Compared to the Q701, this is not an issue.
The 880s have good detail, and are a very evenly tuned headphone. They do everything well but nothing in particular is spectacular. What I mean is that nothing stands out as everything seems equally good. That, to me, is a good thing for a headphone in this price bracket and for an all'rounder.
For me though, I was looking for something that would do well in Baroque and Choral pieces up to modern composers like P.Glass and Max Richter as well as do jazz, rock and electronic. The 880s are the best I've gotten to so far since selling off the more expensive pieces.
If you get the 880s, I'm sure you'll be pleased.
I agree with this. The DT 880 is my favorite of the mid-fi headphone category, along with the ATH-W1000X. I personally think the 880s are much better than the Q701 though. The DT 880 isn't shamed by much higher-end transducers as easily as the Q701s are IMHO.
I had my 880s for two years, and believe me when I say I wish I still had them. As mentioned above, they do nothing poorly, or even wrong, and to my ears they get some things very right. I like how SBranson put it, they are indeed an overall very balanced approach to presenting music. If your source material isn't horrid bright crap, the 880s will give you a nice musical presentation, but as with any headphone, garbage in garbage out so if you throw low bitrate mp3s from hot-mastered pop music, nothing will save your ears at that point. I listen to plenty of electronica now and most of it is actually quite decent to listen to, at least what I have (Deadmau5, Pitch Black, Phutureprimitive, Bluetech, Thievery Corporation etc). I'm not sure what source you have, but if it is a smartphone you may want to consider paying the $4.99 to get Neutron as your music player. It is a really good sounding music player and importantly it has a four band parametric EQ which allows you to "clean" things up where needed without applying really broad sonic changes to the frequencies surrounding the ones you are trying to work with.
Just thinking I'm still in the V-80 thread, of course your not using a smartphone with the 880s! I never did like orchestral music with the 880s, however, that is very likely to have been at least in a big way the source music as I have learned the hard way that a great deal of this material is actually not very well recorded. A friend of mine is quite into this genre and he actually owns a music store that sells hard to find music like orchestral, folk and jazz and he was the one who told me recording quality in classical/orchestral varies wildly with plenty of poor calibre recordings, and based on my listening he is correct. I like the vocal material through the 880s, while not spetacular, they have a really nice, detailed, but not analytical way of portraying the music. One of my favourite songs to test headphones with is a Holly Cole song, One Trick Pony from the album Hopelessly Romantic. This song starts off with a long thundering bass strike that continues and reverbarates as it goes deep and decays slowly, then her smokey voice comes in with plenty of throaty texture. A great test track IMO. Hey, this is my 400 post, nice!
Still can't believe you outright sold them for the D7000s instead of stretching for a little bit and comparing the two first (you can always sell right after the comparison). My D7000s arrive tomorrow and I'm excited to see how they do.