From the time of my graduation with a BS EE (1970) until 1982 I was a staff Biomedical Engineer at a major teaching hospital in Philadelphia. It was there that the importance of shielding, low noise and differential (balanced) circuits was drilled into me. Hospitals are rich in RFI and it was a constant battle to keep it from interfering with a lot of sensitive equipment. Star grounding techniques and shields connected only at the end of the cable where signals originate are standard solutions for RFI.
So, when the idea that wires and cables sound different was presented to me my response was somewhat like pixelthis. However, I wasn't rude and derisive. I asked for proof and cable differences were subsequently demonstrated to me on my own system. Since than I've tried different cables and configurations and hear differences in all of them. Currently I use Kimber Silver Streak which is unshielded! My environment is relatively RFI free so I can get away with unshielded cables. I just purchased some "high end" power cords and will post my findings shortly.
I don't mind saying that the idea power cords can make a difference was at first, to me, as improbable as interconnects sounding different was in the past. I've learned over the the years to close my mouth and investigate instead of saying things I'm sorry for later. So, I'm investigating and will find out for myself.