I have owned the NA eno system (filter + network cable) and currently own the NA muon system and also their USB cable. The stuff is well-made and comes sensibly packaged in a sturdy box. You get the impression of quality.
I might have heard a bit of softening using the eno, but nothing significant or that I considered detrimental to SQ. I do not hear much of anything with the muon in the chain. I could have lived with the eno. These products are isolators using transformers to do the job. Like a lot of this digital stuff, the growth and product development have left purchasers owning a slightly obsolete product shortly after purchase. Such is the current state of the digital world. Currently my isolation comes from judicious use of optical connections with LPSs and I hear no problems or artifacts resulting from those. Some like the NA products because they do not require a power supply. The benefit to you will depend on whether additional isolation reduces noise in your system.
Regarding switches, I use Bonn N8 switches (two) with LPSs and IMO the switch thing relative to the NA muon or eno is apples to oranges. I see no reason you have to use a switch with the muon or eno to achieve the effect of the muon or eno. If you want a switch for another reason, that is a different story.
Regarding the NA USB cable, it is well made and provides a nicely detailed, clear, and smooth presentation. Not warm but also not strident in any way. My best USB cable of those I own.