A comment after the article...
"When I read text of my hard disk drive via USB words are not magically changed, HOT is not changed to HIT. The USB cable and protocol guarantee 100% error free data or no data at all. The DAC sees the EXACTLY the same set of digits whether USB, Firewire or S/PDIF or indeed any and all digital interfaces that uses error correction eg CRC checks that make sure that if the data is not 100% accurate it is re-sent until it is."
I dunno.
OT, I still hold to the idea that the major differences are within the dac chip itself, where the analog signal is born. Just like the dac within your system, if you don't have a good infant signal to begin with...