I've had the anti-cables for almost 2 years now...dunno whats up with them but i can safely classify them as 'directional'. One way sounds good, the other bad. let the good burn in & you have a killer speaker cable for $50 or so.
Weirdo - i hate to say this but lots of folks lop the terminations off anti-cables claiming raw wire sounds best. i got them in bulk, so have no direct experience. somewhere on paul's site it talks about spades & what not... glad you are enjoying them though, i couldn't be without.
boed - you're right there's no way to test for this, but given the crystalline structure of the metal is it not possible one way might let the electrons flow better? these cables are beaten into shape, they don't go from a liquid state to a cable instantly. obviously there isn't much if any 'science' on this topic...but with every set of cables I own listening for harsh vs warm right of the bat has made a big diff. also, anti-cables are not made from super long grain copper, the 100m long stuff for example. with that quality one could certainly argue directionality...isn't.
i never want to enter a debate w/anyone about this, but i will always ask 'have you tried to listen?'. my ears have been beaten by soooooo many live shows & car stereos...but i can hear it.

that said, i have 2 sets of anti-ic's and the sp cables...for me the warm & smooth sounding direction has always worked out best...i follow the bass. paul speltz has made being a cheapskate quite enjoyable!
GD