I have had it for about 1 week. The sound it produces is on pair with separate class A portable amp such as the Aune B1 with more cohesion. The DAC part is definitely better than the Meridian Explorer USB DAC Version 1 that I use to plug in to the Aune B1. In terms of compactness and portability the Chord cannot be beaten. Sounds almost heretic to state this but it is one of the first DACs where I can discern the difference in the way a track sounds, which is something that it difficult to do unless you spend $$$$$ for a very expensive DAC above 1K and more I should state. The Mojo provides liquidity and a dose of excitement to all tracks I have listened through it.
The headphones I have used through it was the Beyerdynamic T1, the Beyer DT1350 MKI and the Beyer DT770 Pro 250 ohm version.