My father told me, heat and fluctuations of signal quality are the death of electronics. A nice clean sinewave and even (within spec) power delivery simply keeps things functioning longer (when I asked for what time lines are we talking about here, he had no idea, he simply said this was a matter of fact in theory, but as to how long something will last, it's impossible to say with the complexity of parts today). He got a Monster power conditioner, and has been using it with his now over 12 year old Plasma television. Not a hint of degraded performance, nor burn in to see. While other folks we know have all suffered issues.
I know I know, that's not proof of anything, and I am way over my head in ever actually knowing if a power conditioner even in theory has any benefit at all.
He also mentioned something along the lines of "dirty power". Not literally in the assumed sense, but he spoke about the current fluctuations from the grid. And sure enough there is a display on the conditioner that indicates current differences throughout the day. Likewise with the input voltage sometimes having the display fade in and out a bit.
I have no idea what this thing is actually supposed to be doing. To me it simply seems like a glorified surge protector or something. My father never thought it could ever provide better picture or sound with respect to digital devices at all. But thought maybe with respect to analogue, mains signal would be a tad less "spikey".
Not my image, but this is what he has. This is supposedly from Monster's actual hay day. I feel like this is one of those devices that does nothing to the performance claims (like you know those Worlds' Best Cables on Amazon talking about burn in, or directional that provide better sound), but simply a device that functions well due to sound construction and decent parts used. So while it may not improve any sound or anything, perhaps it does feed a nice steady and "cleaner" supply of power than straight out of an outlet? Certainly more protection I would hope?