Pros: Smooth detailed sound, lots of features like digital passthru and analog inputs, quality headphone amp, nice price
Cons: USB input limited to 16-bit/48kHz (other inputs handle up to 24-bit/192kHz)
That's a link to my extensive review.
In summary, the Matrix Cube is a cross between the Cambridge DacMagic and the Musical Fidelity V-DAC. It matches the detail of the DacMagic with the smoothness and musicality of the V-DAC, all for a lower price. And don't forget the built in headphone amp, which is very much on par with the Musical Fidelity V-CAN/V-PSU combo. In my humble opinion this is a best buy right now in the $300 range, and would make a very solid foundation for someone building a system.