You will get no real scientific explanations, only psuedo-science, but yes, it is real. I fought it for years before listening for myself about 6 years ago. I am now of the same mindset that you are, that the power cord makes more of a difference than interconnects or speaker cables.
Even after hearing and believing, I still can't understand why, after traveling miles through crappy wire, the last 6 feet would make any difference. I've learned to just file it under unexplained mysteries.
Cheers,
John
