I did end up hooking up the power cord to my video system for a total of about 30 hours when I was not at home. After the final day, I arrived home late, put the cord back into the music system and had a brief listen. Things had definitely opened up some, but it did not bowl me over. I decided the cord was to be returned. The next morning I thought I would give it a final listen just to make sure. Wow, it was as if the cord had been released from a straight jacket! Everything was totally open, transparent, and in it's right place.
The top end was still a little edgy, but that has since smoothed out. Why do your cables behave so differently than the rest? Why do they take so long to break in, and why does moving them affect the sound?
As to the question of why the power cord first, I had been aware for some time that the cord from the wall to the power conditioner was the weak link in my system but I was in no position to replace it. However, when your 40% discount came up, I could not pass it up.
So things have turned out for the better, the cord is everything a cord should be. Totally revealing.