The difference described on the DIY biz web page is that the DAC72 uses the 20 bit Burr Brown 1702 DAC chip while the DAC60 uses the 24 bit 1704. I have no idea how that might translate into performance differences. There may be other differences that are not described, but both models appear to use the same two-transformer power supply and the same parts names (Dale, Oscon, etc) are used in the descriptions. Given the minimal $73 price difference between the $295 DAC72 and the $368 DAC60, if I were buying I would go with the DAC60. The Burr Brown 1704 DAC chip is state-of-the-art. Take a look at the specs in the comparison chart at
http://www.audiodesignguide.com/DAC/dac5.html