This is an interesting thread to me...Since buying one of Alberts' outlets, and installing a dedicated 20a for my amp it has caused me to question all my efforts for conditioning etc. I personally own an RGPC and at this point I consider it nothing more than a boat anchor. I would second AP's overall point here, which is the real results can be achieved at the source much more effectively than through some metal box. Up to this point in my audio career I hadn't dedicated a cicuit, and since doing so, I am very happy with how quiet it is. Before, shared ground, lots of dirty noise, ground loops etc.
I personally am at a crossroads, and I am going to attack the problem of power once I get my new speakers. I will most likely sell my RGPC 600, shortly after I A/B the system, with it, and without it. I fairly certain I will hear no difference, since there is no shared ground on this circuit anymore. I may look for more ways to improve at the source rather than buy another PC. Any suggestions appreciated.