C7 - two prong Power Cord make a difference ?

Not much discussion on this type cord when searching. This is the type of 2 pole connector that fits in dvd player, game consoles, satellilite and cable box, etc. I notice PS Audio, Pangea and Audioquest make them mostly under $ 100.00. Anyone experiment and can attest if these make a noticeable difference or just stay with stock cord. These are C7 polarized version with one round and one square plug end which I believe is standard. I am thinking about purchasing for my Blu Ray DVD player and Cable TV set top box and looking for opinions from Audiogon gurus first. Any feedback is appreciated. Thank you.