Well, I guess I didn't read the article all that carefully (I tend to treat S-pile as bathroom reading).
I checked the article again, based on your comment. The only comparison to the V-Dac was the statement that the ASUS board uses the same Burr-Brown PCM 1792 D/A converter as the Musical Fidelity V-Dac. That's not a bad thing.
I have read some reviews of the V-DAC which suggest that it is sensitive to jitter (and thus choice of USB cables makes a difference). But given your Mac situation, it sounds to me like the V-DAC should be a good choice.
My own preference is to avoid USB. Maybe Gordon's Wavelength/Ayre asynchronous USB solves the inherent jitter issues, but I prefer using ethernet, via a Squeezebox and a separate DAC. Or more recently, for the past 2 years I've been using a Logitech Transporter modified by Modwright with a tube analog output stage. The Transporter lets me input other digital sources, so I can use the DAC as a standalone too, altho it's a pain in the butt to switch back and forth. You can find used squeezeboxes for about $100 or so, and that lets you have all the computer stuff in another part of the house, well away from the stereo.
HTH!