P.S. Audio Quintet? Worthwhile?

Good to know it's not only me - I found that the Duet boosted the treble as well. I'm demoing one now and, while I like what it does in other respects, I'm not sure I can live with the elevated high frequencies. On some CD's its nice - makes instruments sound more "alive" - but on others it makes the CD unlistenable!

Can others comment as to whether the Shunyata Hydra 2 is a better option if elevated high frequencies is my issue with the Duet?

My Duet did not make much of positive difference until I plugged it using JPS Labs Power AC+. I was using a Signal Cable earlier and I'm sure you just need a bigger cable to back it, no need for an AC+! As a result, it made mids sound bigger, gave depth the stage and somehow made the stage more solid. So, I feel invest in better cords before going the PLC route.

In my system, it made a very positive diference, it smoothed the sound giving a more refined presentation. I guess that the performance of the quintet depends on whether you have issues with the ac or not. I did.

I also have the duet and have to say it made a notable improvement in my system. If I have to describe the change, it made the silence between the notes quieter. I live in an old house and I also changed out my audio receptacles with the porter port cryo outlets. It was a pretty cheap upgrade that honestly made a difference.

One of my power line conditioners is a Quintet; the other is an Audio Magic Stealth. Imho, it's a matter of synergy. For me, the Stealth is, basically, better in every way, but a bit brighter. The sound of both is extremely dependent on the power cord used with them. I have had good results using a DCCA Musical Essence, which is very warm and has a rolled off top octave, with the Quintet. I use it for most of my digital gear. Also, the Quintet should be off the floor, on footers. I use a set of Aurios.
It is worth noting that the Quintet, unlike the Stealth, has power line protection.
Also, the Quintet is relatively inexpensive for a power line conditioner. So, it's a question of you get what you pay for. And a case of ymmv.