I teach first grade and I use many types of binders. I need something that will travel well from school to home. I have a tendency to overfill my binders and this can certainly take it.
It has lasted throughout a year of lesson planning - being hauled from school to home and back again. It is easy to open and close and the special cover makes it very durable.
I teach a college class and this type of binder is able to contain all of my lecture notes quizzes and exams in one place. The binder is surprisingly easy to open yet will not allow pages to slip through the ring junctures. I've begun to convert all of my binders over to this style.