I'm in the middle of my first semester of using a flipped classroom. I have students watch videos of the lectures and class time is saved for more interactive activities. These include classroom experiments, classroom activities/demonstrations, and working through problems. Hence, I found this interesting.
The key issue, in my mind, is getting students to watch the videos, and how to handle students that don't watch the videos. On my first exam of this semester, I had the highest ever percentage of students get an A- or A, and half the class got a B+ or better. (I don't believe in the grade-inflation trend, I don't usually have a B+ for my median grade.) While this is only one data point, it provides some anecdotal evidence that for students who watch the videos, they will succeed.
That being said, those who didn't watch the videos regularly did very poorly, however. (All students get one free day per semester where they don't have to have watched the videos. After their free day, I let them stay in class if they didn't watch the videos but they're counted as absent)
Overall, I'm really pleased, as those who have worked hard have learned it. I still need to figure out how to better motivate those who don't usually put in as much effort to watch the videos before class.