You should try some blind listening tests with your friend who claims one power cable is better than the other.
We had sooooo much fun with that for a decade or so with my friends as we'd come over each other's homes and compare the cables we would borrow from the cable company lending library or an extended audition from one of the local dealers or just something we had in our systems.
Every once in a while we'd come across a PC or an IC that would stand out just enough to pick it as a winner on one of the musical pieces we'd play but never universally on a playlist of more than a few songs.
Try it, it is fun.
