There are other folks that have had the opposite experience, finding that a regenerator diminished the sound quality and a Puritan system improved the sound quality.
I believe it has a lot to do with a variety of differences in AC from home to home and also the way ones components interact with AC.
There have been many threads and reviews of Puritan products over the last four years or so. I think it's accurate to say that for every 100 Puritan users, 98 or so, after 200 hours, find it beneficial and a couple do not.
I use Puritan products in both my consumer stereos and three production studios, two of which are at different locations. In each case, I hear a worthwhile benefit. It's especially apparent in the production studios.