Indeed it's a cracker and sounds rather brilliant when used with Pure Music & iTunes on the MacPro, the most recent release below is 100% cooking on my rig !
http://www.channld.com/pure-music4.html
Also, in case you have missed these:
http://www.6moons.com/audioreviews/m2tech/hiface.html
http://www.enjoythemusic.com/magazine/equipment/0210/m2tech_hiface_usb.htm
http://www.computeraudiophile.com/content/Just-received-M2Tech-Hiface-USB-interface?page=4
http://www.channld.com/pure-music4.html
Also, in case you have missed these:
http://www.6moons.com/audioreviews/m2tech/hiface.html
http://www.enjoythemusic.com/magazine/equipment/0210/m2tech_hiface_usb.htm
http://www.computeraudiophile.com/content/Just-received-M2Tech-Hiface-USB-interface?page=4