The agrument, in my humble opinion, falls apart when you consider that an exotic PC represents the last few feet in a very long feed from your utility. A feed that is NOT shielded and is subjected to all sorts of harmonics and other nasties. But hell, if there were no self deception, this hobby it would be no fun at all.
There's a school of thought that suggests that from the amplifier's perspective, an exotic PC represents the FIRST few feet of a very long feed...
I'm actually on the fence on the whole PC debate at present, because I've not actually performed any experiments of my own (and I'm not talking about DBT!). So like all things audio I haven't actually experienced myself, I remain open-minded but a bit sceptical.