I had one professor in college (Physics) who taught using this model. I created pod-casts for all his lectures and sent then home as homework. Then during class he would work problems (designed to teach key concepts that lined up with the pod-casts he had been sending home), it was a great model. Given this was a college introductory class, so about 50 students. It worked well. He had the lowest drop/fail rate of all the other professors, who taught the same class material. I have long found working example problems for Math/Science classes to be the best way to prepare for an exam. This model of flipping what is done during the classroom time, definitely works. I hope more educators adopt his model or at the least try it out.