Quick overview of my experience:
►Definite improvement from $10 stock cord to $100 level after market cord on every component. Usually heard in elimination of background ’noise’. or just improved power delivery
►Once a system is built that is close to one’s ideal (say a 7-8 out of 10), then power cords can make another medium/large step toward that ideal (to reach that 8.5-9 out of ten level). At times, I’ve noticed connectors can contribute significantly (almost as much as the cable) in some cords (think Furutech, Oyaide, etc.)
►Cable size, geometry, materials (copper, silver, carbon, air dialectric), and cryogenic or ’cooking’ treatment can definitely contribute to achieving that ’last mile or two’ of performance/preference.
► After starting with Bob Crump’s (TG Audio) cords over 25 years ago, I’ve probably tried 30-40 different power cords over the years, with mixed results. I’m currently using a large diameter silver power cord (Tek-Line) on an amp, smaller diameter diameter cord on transport (Acrolink 7N4020III w/Oyaide 004 connectors), and Argento Flow Master on DAC. Electraglide or other ribbon cord(s) on things tubed, especially preamp. YMMV.
►Like most of us, I have quite the collection of power cords, interconnects, speaker cables in the [big] boxes in the closet. And I must say, most I actually liked at the time; just moved on to 'better(?)' 😊