I will throw my hat in the ring as a happy Puron customer as well. Bought 2 of them and I perceive a significant audible improvement in both soundstage and the depth of the soundstage. Definitely worth the $400 I paid for 2!
Smaller plug-in AC Purifiers -- Shunyata, iFi, Puron...something else? What do you like?
I like the Shunyata Venom Defender. It does a good job of reducing noise in my outlets.
I'm wondering if others have tried similar, plug in products — such as the Puron Power Filter or the iFi AC Purifier or something else.