I had the Puritan and now have a PS Audio P15. The Puritan had a subtle negative effect on my system, I loaned it to a friend and he had the same experience. I ran it for a a couple months and it was a breath of fresh air when I removed it.
The effect of the P15 was a subtle improvement across the board. What it gives me is consistent sound any time, day or night. What I call Sunday night sound, now 24/7. I have two direct lines to my breaker box, and pretty clean power to start with I think. For someone living in a noisy power zone, I suspect it would make a significant difference. I ran my power amp through it for a couple months, but switching it directly to the wall was an improvement. Everything else has benefited from the P15.

