Not sure why other than the producer says so and got a bit of favourable press at recent audio shows, but the Empirical Audio Overdrive SE (at $5k) makes great claims. If I had that sort of coin to spend on a DAC/pre combo I'd be interested, but for now I'll be content with my Audiolab MDAC. I am viewing the MDAC as a transitionary component as I don't like that it doesn't do 24/192 via USB and while a great value the pre doesn't make the claims the Empirical does. My price limit on this sort of combo is $2k - the Burson Conductor also looks like it might fit this, but reviews don't seem to put the pre- on the level of the DAC