I found most of them pretty basic. For example, the latest one I've watched was a series about evolution and genetics and most of the information wasn't new because it's actually a high school program. Anyways, they are not too basic and can be really helpful to refresh the knowledge. Some of them can be really sophisticated as well. As for the performance and streaming, they are really good and I have never had any problems with them. I love the ability to do a homework and share the knowledge with other people, it's really nice