I'm a believer in letting it run. I have a Yamaha mixer in my office that has not been turned off in maybe eight years and it runs like new.
The technician who works on my gear when necessary tells me the same thing--it's better to let it run than turn it on and off frequently.
I only have personal experience with this, not any sort of technical expertise.
The light bulb in my closet is always on. I can't remember changing it, but I do know it has been several years.