Here's my subjective take on the subject...
I've had, at any one time in my system,either purchased or borowed for a listen, ones from Monster Cable (what a waste of money!).. Audience AR12t(very,very,good!)...Shunyata Hydra...Running Springs Diemetri, Walker Audio and a few others.
The one that did the best job with the least negative effects and made the music more enjoyable was the last one I'll ever purchase,or need...the Bybee Power Purifier V2.0.
Absolutely,without question, put them all to shame.