On the east and west coast, I've met quite a few teachers, and none have a 3 month break every year. Maybe a few weeks, but they are frequently tasked with continuing education or some other task during the summers. And during the year, they're always working 12+ hour days.
I think the "always working 12+ hour days" thing is a myth. My wife is a teacher and I would say her and the teachers she works with will occasionally work extra hours, but by far it's mostly 7.5 hour days (8:30am - 4pm).
I think that's the difference between a good teacher and an average one. My wife was a teacher (left because of the poor salary). She worked 12+ hours a day five days a week (we made sure to keep weekends open but we were there on weekends too sometimes). You could see which other teachers were there 12+ hours. It was the ones that sent the most prepared kids to her class. There was an obvious quality difference between the kids who had teachers that worked 12+ hours a day and those that didn't.
Depends on the grade and subject. Some teachers have a whole lot more grading to do than others. And some grading or planning is slower-going than others. Also some schools are better about keeping time clear during the day for teachers to plan & grade than others.
New teachers are the ones that get the 12hr days. I knew a teacher that told me the early days were hard since he had to develop the lessons and there was a learning curve too but at some point, his days got shorter and it got more enjoyable.
