I previously had my entire system plugged into a API Powerwedge 116. I was intriguied with the talk about the P300 and bought one. It was a major improvement over what I was using. The Powerwedge did seem to reduce the noise floor, but what I didn't realize was that it was muffling the dynamics and sort of greying the sound. I was of the mindset that the powerwedge must be better than nothing. I left my amps plugged into the Powerwedge because the P300 can't produce enough power to power the amps. What I was really amazed to find was how much better my system sounded when I plugged the amps directly into the wall. It really made my system more dynamic and lively. My point is don't assume that a power conditioner will always be better, I do agree with the others that the PS Audio Powerplants do make a big diffrence however. Also Carl is right about the hum that the produce, it doesn't come through the speakers but directly from the unit. I can barely hear it from my listening position which is actually kind of irritating
