Personally I don't like it, but I can see why other people may. For a broader angle drier approach to these see: http://www.head-fi.org/t/614011/sennheiser-hd700-review

I found this DAC kind of meh. $699 (currently on $669 special) is sort of no-mans land is terms of DACs. It's admirable that Matrix put out something at this price point - especially balanced outputs. In terms of my expectations at $699, I wouldn't expect the utmost resolution, but I would at least want something that doesn't do anything terribly wrong.    The impressions below are from the balanced outputs (I think it's fair that this review focus on that, after all, this is a balanced out DAC.) The amp used was an Eddie Current Balancing Act...

    EXECUTIVE SUMMARY   1.      Not coherent throughout the audio band: a. Overall neutral, but but but b. What’s up with the peaks in the upper mids/lower treble?* c. Little bit bloated in the bass d. Bass not keeping up with the mids/treble 2.      Little bullet design = comfort/fit that blows monkey chucks 3.      Mid-fi resolution 4.      Aren't IEMs supposed to isolate?   Significant sonic issues indicated in red.     * Pop and rock do not sound good. However your results may be better with classical or music with...

Too much bass, strident treble. I guess it could be worse. Midrange is not bad. It might sound OK straight out of my out of my cheap Android phone which lacks power and sounds kind of muddy.   The treble hurts me. I wouldn't keep them though, even if someone gave them to me for free. I wouldn't give them to my kids either because I don't want to destroy their high frequency hearing.   Really ugly too.