Many people in the head-fi community disappointed by the new denon lines, music maniac. But i think the other way.... well, initially when i got mine, the design  and presentation was jaw dropping, but the sound signature was horrible, it was bright and harsh treble with muddy bass. After burn-in them for 10 hours the treble settle a bit but the bass was still sound muddy.  After 40 hours burn-in, it was totally different headphone,wide and airy sound stage, smooth treble, and strong bass. I  can dare to compare to many high-end headphones. 
 
Audio Quality - Bass - 8/10
                      Treble - 7.5/10
                      Mid - 6/10 
                      Sound stage - 7.5/10
                      Vocal - 8
                                           Overall audio quality - 7.4/10
Isolation - 6/10
Leaking sound  - 6/10
Durable - 9/10
Presentation - 9/10
Design - 8/10
Comfort - 10/10
                                           Overall headphone rating - 7.8/10
 
Conclusion
Denon ah-d 7100 requires minimum 40 hours burn-in to enjoy your music. i think suitable music for the headphone are classic, jazz, and rock. 
Note - i will try to re-evaluate  after 100 hours burn-in