Speed and clarity are staggering for a bass-heavy closed back headphone. They're really reminiscent of a planar magnetic in that regard. I have two other bass-heavy headphones I'd compare them to: the Sony MDR-Z1R and Klipsch HP-3, and in terms of speed, the DT1770 runs circles around them, despite having more boosted bass than either.
The treble is where you might run into trouble. I like a headphone with a bit of a boost to treble, but at high volumes it can be really grating, and the DT1770 especially doesn't do well at high volumes. I'm a low-level listener, so I sit around 75dB, and if I decide I want to jam out with some loud listening... Well I pass on the 1770.
That being said, if you find yourself not totally engaged in music at lower volumes with most headphones, the 1770 might give you a chance to get some of that energy in low-volume listening.