I have a couple of these and have been using them for many months. I plugged one on the line that feeds into the switch from which all my audio gear is connected, and another into the NAS that stores my files.
It was not a revolutionary experience but to my ear did no harm and I thought the overall presentation of the music was better with them in play. I might agree with your description you posted above regarding tone.
For the modest cost of these I don’t feel taken and happily continue to use them (along with my AudioQuest Jitterbug and Emotiva DC blocker) while enjoying my system.