When I was getting back into Audio a few years ago, I purchased a $100 Silnote power cord for a NuForce STA-200. The change was HUGE! My deaf mother and father could have probably heard the difference.
Pass Labs and First Watt includes a very substantial generic power cord with his amplifiers. I have tried various power cords with his amps, some I liked a little better than the included cord and others I did not. In several emails, I attempted to get Nelson Pass to recommend an aftermarket power for his equipment. He has always stated that the cord he sends out is very good, but never indicated that there might be cords that some might like better. Getting into the power cord recommendation business might be a rabbit hole that Nelson does not want to travel.
In my system the BorderPartrol DAC responded quite well to a aftermarket power cord.
From my experience, Horn speakers and single driver speakers are more resolving than other more conventional speakers and tend to reveal changes in cabling more readily.
To disagree with the double naught spy crowd; in a good resolving system it all matters.