What is wrong with your current cable? If you need a new power cable because of some damage, just get a direct replacement.

Others will say after-market power cables are hype. I never tried one so I can speak one way or another, but I have a hard time imagining that an expensive power cable can make a difference since the AC power is converted to DC in the unit itself. Fluctuations in power is a known issue and I would hope the designers of the AC to DC converters would take this into concideration. AS a matter of fact, I believe that is the reason why components use DC!