Rwwear, I'll pick up cordially on your comment, "My assertion was for those unfortunately hard of understanding is that you can not compare dozens of cables and remember what the first one sounded like. If you can, you're an amazing person."
Well, thank you, I guess I'm an amazing person, because I do recall what the different cords did in various systems. If you would compare sets of cables like I do you would likely hear the "character" or specific sound of the cables, which in reality is fairly easy to categorize, similar to taking a drink of a new beverage. I do slot cables into mental categories based on their use in multiple systems. I do believe that if I were to return to those cables again I would hear the same effect from using them, just like returning to the beverage once tasted.
Now, is that amazing? I don't think so. :)
Anyway, to return to the topic of the thread, I do not need to remember the sound of dozens of types of cables to prove my point. I need only argue that there is a sonic difference between two types/sets of cables. There is no point in my arguing that I can recall various cables, but there is a good point in my arguing that any given set of two cables likely will sound different from each other. If you wish to apply this argument to power cords specifically, feel free, as I believe it pertains.
The pertinent question now is, Rwwear, have you actually conducted comparisons between sets of cables? Merely listening to "everything out there" is not the same. And frankly, I do not care how many years you have been in the audio business; this is not a matter of time in the game, but rather specific experience which you may not have. Have you run listening tests between two or three brands of power cords? Have you tried two different sets of cables (power/IC/SC)?
If you have and didn't hear the difference, I respect that. Then simply say so. But if you haven't, then you owe it to yourself to try.
Mapman, yours is an interesting argument technically to say that IC/SC is in the signal path but that power cords are not. I take a very pragmatic approach to audio; if it influences the sound, it's considered efficacious. I think we would agree that if power cords do influence the sound it would be due to being far more directly involved electronically than various tweaks which have at best only a physical contact to the component and at worst no contact nor demonstrable influence upon the sound waves.
So, in practical parlance it matters little to me if the power cord is "in signal" or "out signal" - I find they alter the system performance powerfully (pun!). They influence the electronics which influence the signal.