Is it all in my head??

Nobody can explain it Nonoise, that's the thing. 

Power being good and not varying has almost nothing to do with it. Power where I live is very good if you measure it. All you do is listen though and its obviously a lot better late at night. 

Also almost all noise is local. The worst noise is within your own room and home. Anyone can confirm this very easily. Simply play some music, listen, then go flip off as many other circuits as you can. Come back and listen to the dramatic improvement, better than almost any power line conditioner you can buy at any price.

Unlike power cords where nobody knows why, its pretty obvious why this works.

Nobody really knows why or how these things work. If anyone ever did then in no time flat everyone else would too and the resulting competition would drive prices to the floor. That hasn't happened. Because no one has a clue. Just stories they tell to customers who haven't yet figured out design don't mean squat. How it sounds is all that matters. So really, they don't design, they experiment. When you have to throw away a hundred that sound like crap to find one that sounds good then of course you have to charge a fortune for that one percenter. But then not all "designers" even get to the 1%. When you can't sell the sound, sell the story. Always some engineer or wannabe who can't hear (or won't trust his own ears- happens, trust me) eager to buy the story. This is power cords, interconnects, speaker cables (everything, really- turntables, speakers, cones, footers, equipment racks, on and on, the whole friggen industry) in a nutshell.