I've only heard positive things about it, but no comparisons with other mainstream pro/semi-pro adc's...
For a soundcard, my eMU 1616m does double duty...
From the Mytek and Lavry ranges have their respective DAC's - which are just as highly regarded as the ADC's (perhaps more so, as they are better known among audiophiles...)
On my office PC I picked up a used eMU 1212m - PCI card based, which runs into a headphone amp... results have been excellent. (chalk and cheese from the previous M-Audio 2496, the onboard soundcard, etc...)
My partner uses one of the Asus Xonar soundcards on her PC - which she likes a lot - but I have not done a comparison.
bye for now
David