AQ, Shunyata, Isoteck, Torus are all filters with their own technology. And Voice. I was pretty pissed when TAS did an article on power conditioners and failed to mention an isolation transformer. Isolation transformers are in most every recordijg studio around the world for 2 reasons. One they work. 2, Art kelm who specifies that work finds they work best and uses them. I like them as I have never heard one do negative things. Only positive. And I can feed any amp. I always am aware what any of the other filters are doing.
If you hear noise out a speaker, that is ground or equipment issues. Its not dirty power. You deal with the issues in different ways.
If you read Arts site, you will see he calls out metal wire and isolated grounds in his cable runs and associated panels. There are reasons to like metal. IMO, its not about geometry or performance. There are other reasons to like it. But the positives of metal can easily be overcome in NM when installed correctly with the rught materials. . And you don't end up with ground issues. NM reliably works. Filters are doing a job that addresses noise on the power line proper wiring or metal encased wire do nothing to address.