I'm currently using an Apogee Duet with my MacBook Pro and Denon AH-D7000's. I like the increased depth and better bass than with the MacBook headphone out, but the Duet seems to make things sound "rounder" and more "glued" together. I use a Sound Blaster card at home, and although it is noisier and smaller sounding, the mids and highs seem to be delivered quicker and with more precision than the Duet. I would also like something that is cross platform. I have been considering the Nuforce HDP or the RSA Predator. A seperate amp and DAC is not out of the question.