Otherwise, I almost never power off my phone. I do switch it to airplane mode when I fly, and set it to silent when appropriate.
I turn it off in flight, sometimes. Airplane mode otherwise.
Very rarely off completely.
Also, an incidental reboot happens because the battery runs out.
It's not very important to me. I live in a rural area with bad coverage, but more importantly--I own a computer, and I spend most of my day on it. I can't see the use for my phone when I'm sitting at my computer.
When I was on-call, and then got a weekend off, I turned it off. Someone always tried to call. But I'm not in that 24/6 space anymore.
The only sound that plays is sound that you specifically asked for, like music or sound from a video, the alarm and sound from badly behaving apps.
"Unfortunately, where you listed the example of 'badly behaving apps' as one of the sounds it does play, this shows that in many cases the only way to be sure that it will not play sounds is to turn the power off. That is the only way to know this will not happen."
Maybe it's a quirk of this particular model (iPhone 5), or some sort of bug, but it's definitely making the low battery sound while physical switch is set to mute.
Do those of you who turn your phones off or leave them places not have spouses/children to be responsible for, aging parents/grandparents to help out with, or in generally want to be available for friends when they need anything or just want to grab a beer and catch up?
I very much want my child and anyone who may be charged with keeping them safe to be able to contact me 24/7. Too much can go wrong too fast to not be able to be there for those that I care about.
Almost unheard of these days (depending on where you live).
Personally I never switch off my iphone or even set it silent, but after years of living an event-driven life I learned to ignore those interruptions.
Good point about children: I dare not be incommunicado during the day.