After Market Power Cables - Gold or Snake Oil?

I don't understand much about electricity or why "better" power cords make a difference. I only know what I hear -- and I hear a BIG difference. Skeptical, like you, I picked an inexpensive used one at first and I was sold on power cords. I've bought some better, "moderately" priced ones since (Shunyata, JPS) and am very pleased with the results.
Try one for yourself. I don't think marketing hype would generate the continuing sales of power cords if there weren't results to back it up. I don't understand why they make a difference, and I'm not happy that I have to spend money on ANOTHER expensive "tweak" to my system, but that's the way it goes.
The only analogy I can make is to a water filter. We get our water from an everyday water faucet, but the addition of a water filter makes an appreciable difference in the water quality -- you can taste it just like you can hear the difference with a better power cord.

Checkmate110, I don't understand how they work, but they do. You do bring up a valid point about plugging it into an everyday wall socket though. I have two 20A dedicated lines run for my A/V room, using PS Audio Power Ports as receptacles. I found that this difference made a larger improvement than the p/c's. The p/c's do make a difference though. Why? I cannot explain that part.

If you have about a year of extra time, read through all the threads on A'gon. I think with everything, you need to have an open mind and experience for yourself. I do and am glad for it, my system thanks me everyday.

Matty