The D2000 has a fairly nice soundstage, but the DT990's sound stage is much better.
The overall balance of the sound on both of them is very similar for both being completely different cans. They both have a u curve, but the D2000 extends much deeper. DT990 might be good to about 50hz, but D2000 is solid all the way down to mid 20s hz.
I think D2000 would be your choice for dubstep etc.
Both are comfort juggernauts. The DT990 has a better long term comfort by a tad amount, and is very spacious. However, the D2000's fit makes the DT990's fit very clumsy feeling. I'd say D2000 has way better short term comfort.