While I don't think the PS3 will benefit from an improved power cable, I do think higher powered amplifiers, subwoofers, and projectors can benefit.
And with these devices you have to weigh out the return on you investment. You will never see an improvement of double. But when a customer of mine wants to get every last bit of quality out of their system WITHOUT changing gear, things like speakerwire, interconnects, power cables, ROOM TREATMENTS, isopads for sub's and speakers etc can give you that little extra.
This topic is like atheism vs spirituality, and both sides are whack. The audio atheist wants to beat the system and tell the whole world that they did a scientific double blind test and it proves that the pre-opinion was right. Placebo effect working in a different way.
The audio spiritualist will tell you that you a dumb and not loved if you don't have better cables, wire, and that there is a heaven of audio quality awaiting you on the other side. There is not. These people are either bad salesman, or audio snobs.
And then there is the real world guy like me, who would prefer to look\listen, on my own, with no bias (which I have done, in my own home, with my own equipment), and draw their own conclusion.
The last option is what everyone should. Have your own opinions after completing your own tests.
Next time a salesman tells you that a cable makes a huge difference, call him out on it. Ask him to try one out at home (for free, or purchase and return for refund). Test it out yourself, in your controlled environment away from the audio atheists opinions online, and the audio spiritualist at the store. Be an audio realist.
Custom Home Theater Sales Specialist.