These are the first 2 paragraphs from Puritan Audio Lab's product page:
http://www.puritanaudiolabs.com/products/master-purifiers/psm156/
The PSM156 builds upon the brilliance of the legendary PSM136 retaining the precision symmetrically balanced circuitry and 6 fully independent outputs. Increasing the number of independently tuned filter elements from 39 to 52 enables your system to deliver even greater delicacy and detail whilst enhancing dynamics and punch.
The PSM156 will lift your system into a new dimension. Definition takes an enormous stride forward, individual instruments gain air between them with their sound and timbre becoming believable, the sound-stage will move out of your speakers and into the room with gains in three dimensionality with clarity definition and space between the instruments for them to interrelate rather than muddle each other. Your listening will become a far more engaging and pleasurable experience.
I didn't see any wording that says the product is only beneficial if your AC is "bad". (And if it is only beneficial if you have "bad" AC, then give the detailed definitions of what "bad" AC means, so people can determine if this product is useful for them.) They claimed their product improves sound quality, which is disproved by Amirm's AP measurements. Why are Amir's measurements wrong when he is measuring against the manufacturer's claims?