Honestly, even if James says there is a small sound improvement, I think this is all imagination and placebo.
I bet that in a double blind test you would not be able to differentiate between gear that has been turned on for a long time and one that hasn't.
I can understand that a professional studio doesn't want to switch on and off all the time.
But private use? Come on. Snake oil that cost you money!
If an electronic device is not stable and at max. performance after some reasonable warm-up time, it is poorly designed, period. Of course, if you believe that it sounds better over time, you WILL hear it. Even if your wife turns it off while you're not at home...

Face it, there is no magic in electronics. The magic is in your brain.
BTW: Lightning protection is useless if a lightning strikes near or into your house. Do you think that a small protection circuit is capable to block an up to 100 kA lightning?? Heck, the electromagnetic field can induce high enough voltage/current in your equipment cables to damage your components even if the power cord is not plugged in.