Tooter,
That's a first for me. I've never heard that one. One way to find out is to contact Robert Lee at Acoustic Zen.
InfoZen@AcousticZen.com
One thing to consider though. A couple years ago, I bought a BAT VK3i to pair with my BAT VK200. I was at the time and still am using exclusively Acoustic Zen interconnects, but they were all single ended. On the advice of Victor Khomenko of Balanced Audio Technology I bought a balanced version of the Matrix Ref II to run in between the VK3i and VK200. When I compared the sound when switching between an RCA Matrix Ref II and a balanced version I could hear no difference at all.
If you peruse the discussion forums you'll find examples of people realizing huge sonic gains when connecting gear designed to be used in balanced configuration, so I was shocked I detected no difference. When I mentioned this in the forums someone remarked that it's possible the Acoustic Zen Matrix II with XLR termination wasn't a true balanced design. I never confirmed this either way, but it is something to consider when someone says that the MC2 was designed to be used as a balanced connection. It would be best to ask AZ directly.
Good luck!