@chungjh We have a P20 and customers running the P15. The P20 easily supports our smaller amps and the rest of the system. We've also worked with the Elgar power conditioners and have customers running those. Some of them are so large you can literally run the entire audio room circuit off of one conditioner.
Most conditioners IMO are glorified power strips. For them we generally recommend running our amps plugged directly into the wall.