I think some of the difference in experience may be attributable to the quality of the "unconditioned" or dirty power. I don’t use any line conditioners on my main system except that the 10kVa isolation transformer on which the system depends has a surge protection board. And I have a basic, "whole house" surge protector.
I have used various aftermarket surge protector power conditioners over the years and though my experience may be dated, found that they all altered the sound. To the extent of throwing "baby out with bathwater" I concluded that the conditioners I tried at that time were compromising the sound, but I could see instances where a conditioner might improve the sound of the "dirty power."
PS> I listened to the system without the iso transformer for almost two months before it was installed, and though a little "bright" at first--burn in?- the addition of the iso transformer did not change the voice of the system. I think the infrastructure where I am near downtown Austin is far newer than that which I had in NY metro. So, I’m not sure that there is a universal conclusion applicable to alll systems. What’s your power like out of the wall? And what can you do to improve the quality just using. basic best practices, without voodoo. That’s where I’d start, before adding any black boxes (of which I have plenty).