My experience has been that it depends to some degree on your components. If you have a tube preamp, a good cord makes a significant difference. My Joule Electra preamps have always liked the old school ribbon style (Electraglide et. al.) Next would be the source. But pretty noticeable tailoring can be done on the power amp side too. I can easily tell the difference going from stock cords on my amps, to Pangea 14SE or 9SE, to TG Audio HSRi, to a 9 gauge silver cord, and up, etc. I suspect many of us have a box/closet full of many that have fallen by the wayside, especially because once they are bettered, there's usually no going back.
Power cord replacement suggestions
If i were to delve into the fanatic behavior of replacing power cords, is there some concensus on where the most impact would be gained, whether on source, pre, or amp, or is it just different for every system and need to experiment. Thanks for any advice.