The DT880 (600 ohm) are my favorite reference headphones for listening to music with.
I do love the AKG 271 MKII for judging vocals though. For example right now I am listening to Third Eye Blinds self-titled album on the 271 and they reproduce Stephan Jenkins voice so naturally and beautifully. A lot of speakers and headphones that don't get the mid-upper midrange correct, his voice will sound over nasally and sibilant. They won't accurately reproduce the slight lisp he has either. This is one album I use for reference.
The DT880 is the total package though. The only thing I would be afraid of is sound leaking into mics for monitoring purposes. But if you can prevent that they are the overall better headphone. I do love how the MKII mute when you take them off your head. They are really what you can call a headphone that was made for professional use in studios.
