Here is a quote regarding the "powerplant" .
It seems as if the "reviewer" is claiming that the powerplant actually affects the quality of the sound in his system - not by only removing "bad stuff" (techinical term of art) from the electricity flowing to his equip. - BUT actually improves the soundstage/focus of the individual performers in the music.

If this is the case - then the line conditioner is not just a surge suppressor with a filter,and an insurance policy, but actually an audio component in itself -

"I've had a chance to listen to the P300 for a few days now, and I've had a very hard time tearing myself away. This is a stunning product! By comparison, my old conditioner "homogenized" the sound, so everything had the same filtered quality. With the P300, the individuality of every performance and recording is so much more distinct." PA