It is hard for me not to be be a sceptic when I read claims about hearing the differences between digital cables, especially when used with modern DACs which reclock the signal anyway. It's not that hard to test the bit accuracy of a cable. take a .wav file, make a md5 file for it, send that file to your DAT deck or CF recorder, transfer it back to the PC and see if the MD5 checks out. Bits is bits...
Optical cables are also much more immune to RF...
-Noah