I had the 250ohm, I couldn't find anything I didn't like about those except a little light on the bass and recessed vocals. The 600ohm fixes both of those amazingly, I think. It's not hot on the treble at all, compared to the HE-400 which made my ears ring for a week straight. I like the HD650 for when I'm in the mood for slower songs and richer vocals, but the DT880s reproduce electronic music the way it was meant to be heard, in my humble opinion. It is simply the perfect headphone for it, again, in my opinion. The majority of my music is electronic. It just stimulates my brain in a way little other music can. So to you I say, I haven't found many cons with the sound. I love it.
Ah..there you have it, the DT880 is better for electronic music, while the HD650 does vocals/acoustic/jazz better. Depending on your collection, you may use the DT880 more, but some songs will always be special with the HD650.
I have a similar thing with my IEMs, the Shure SE425 (smooth, mid centric) vs the TDK IE800 (neutral). I enjoy them both, but they're both magic when there's a perfect headphone/song match.
Edited by proton007 - 1/16/13 at 7:50pm