If you haven't already, I'd actually recommend you get a pair of quality interconnect cables before considering a power cords.
I think power cords can make a substantial difference. But that is not to say the stock cords sound bad, or are inadequate. To put things in perspective, I would only consider a power cord upgrade after source, headphones, headphone amp, interconnect cables, and headphone cables are "there." Also, I am not aware of any "consensus" that p.c. don't make any difference - plenty of people on Headfi would rather listen to aftermarket power cords. Some people claim they hear no difference, and I believe them (because I believe they are honest) - there are many things to consider - your listening environment, listening volume, quality of your AC, etc. But honest people could make mistakes - once some guy with a pair of new headphones posted that the phones, as they break in, he needed to turn the volume pot up to achieve the same normal listening volume. He probably listened too long trying to analyze things for hours and yet his conclusion was that "the (headphones) drank more juice as they break in." It's people's perception. Disclaimer: I'm merely encouraging you to try, not buy.
Finally, replies aren't necessarily in order of correctness.