The D2ks are certainly not what I would call "well rounded". They were pretty bass heavy and warm sounding. If you want something 'well rounded', but still sounding like the D2000, I'd easily recommend the Mad Dog headphones. If you want something that sounds similar to the D2000, I'd go with M100 or m80 from V-moda, ultimate ears UE6000, Sennheiser momentum or HD25, AKG K550.
What kind of music are you into?