DAD22,
I hate to sound so cynical, but the benefits you outline aren't likely to happen frequently in practice. Although some teachers individualize instruction, most will keep students together. Students who have mastered a concept will likely be used to "help" their classmates who don't get it rather than accelerate. If textbooks are any indication, I doubt the videos will include the variety or be of the quality you hope for. I don't think watching the same video over and over will help students to achieve true understanding, so class time will be used by the teacher with the help of students who get it to teach those who didn't learn from the videos.
