Fbi,
I am doing exactly what you describe, running a dedicated 12 ga. line, terminated with a Marinco IEC plug, powering a PS Audio P300. Another identical dedicated line feeds a PS Audio 15 amp high current Ultimate Outlet. I have my Martin Logan speakers, pre-amp and CD player plugged into the P300, and 2 amps plugged into the UO.
I never tried to use an outlet between the dedicated lines and the PS Audio equipment, so I can't give you any comparison there. However, I did have everything powered up via the same PS Audio equipment plugged into a standard wall outlet, minus the dedicated lines, and there were obvious differences with the addition of the dedicated lines. (Specifically, greater bass extension, more open soundstage) I suspect that it was a combination of the addition of the dedicated lines, and the elimination of the connection points required for outlet in the circuit.
I can't see that there could be any (sonic) advantage to adding an outlet if given the option to directly connect a dedicated line to a power conditioner or component. However, I agree that it probably doesn't conform with code. I don't think it is really a safety issue in my house, since I don't have any children around who might try to stick an energized IEC plug in their mouth (or any other orefice).
And.....since this thread started with a discussion of Wattgate receptacles, does anyone have experience with the Wattgate IEC connectors? I am wondering if this might be a worthwile upgrade at the junction of the dedicated lines and PS Audio gear.
Thanks,
Mike