I've been using the flipped classroom model for the past two years in my high school math classes, and in general I'm a fan. I got started with it because I liked the idea of students doing the more passive watching-a-lecture-and-taking-notes stuff at home, then doing the more active/challenging problem-solving type work in class. Also, it's a great way to cut down on the teacher exhaustion caused by saying exactly the same thing multiple times a day.
Homework completion, however, was an issue that I never really resolved to my satisfaction. With my honors classes, the homework completion rate was around 90%, about the same as it was for non-video homework assignments. For my non-honors classes, however, the homework completion rate was around 50%, again about the same as for non-video. I decided the low homework completion rate for my non-honors students was less about not having access to a computer or internet connection at home, and more a reflection of the fact that they just don't do homework consistently in general.
When I began teaching Common Core Math II this semester, I was faced with the question of whether/how to incorporate video lectures in this new course. I decided that, for the topics for which I had video lectures, I would plan to show the videos to my students in class; they're all relatively short, and it would eliminate the issue of a sizeable chunk of my non-honors kids not watching the videos. (I still assign videos as homework to my honors students on occasion.)
And I've discovered I still like having video lectures, even if I'm not assigning them as homework. They're available for students who are absent, or who want to use them to review topics they're struggling with. They eliminate the need for me to repeat myself several times a day when giving the same lecture to multiple class sections. And they allow me to convey the material much more efficiently than in a traditional lecture (a point Lodge McCammon makes very well in this video).
So I'm still a big fan of using video lessons in my math classes. I'm just not sure if my classes qualify as "flipped" anymore.