I leave my DAC on almost all the time, but it's power consumption is minimal unless playing high resolution music. My SS integrated is AB and I leave it on a lot because I rarely get to sit and just listen for an extended period of time, but it does really well even when first powered on.
OTOH, I have some Class D amplifiers that do really poorly for music until powered on for 3-4 days. They are very cool running though, with minimal power consumption when not playing music.
Your mileage may vary. :)
I do want to point out we are not always aware of or home when power surges hit. I'm obsessive over surge protection in this home but if I know a storm is coming over night I still turn everything off I can, including the surge protectors.