My Take
The kids thought this was helpful to have as an extra resource for some skills, but I am not impressed with the number of teachers jumping on board to give more lectures in a different way. If it's used as a way to provide extra help in ADDITION to meaningful instruction or inquiry learning, that's one thing.
How I Use It
I used these as supplements for students who might be a) more interested in a topic we didn't get to in class or b) as an additional resource for kids who needed the material again, or repeated, or presented in a different way.