Tír Na HiFi

I had a (significantly cheaper!) power regenerator on my CDP back in the day, and I found it genuinely very useful. Prior to its insertion I had very inconsistent sound, and at peak demand periods things would disimprove markedly. I told a story here before about listening happily one evening when suddenly the magic was gone. I asked my wife if anything had happened with power and it turned out she'd just put on the kettle.

Anyway, placebo or not, the regenerator fixed all that. The only downside was the efficiency (as you've already discovered) and the fact that it had a little fan that was occasionally audible.