Has anybody had any success with a college level "flipped classroom?"
Oxford and Cambridge University courses in England have always operated a bit like this.  In my Oxford Maths course, I'd attend 1 or 2 1-hour long lectures on the subject, have worksheets to do, then have classes in college of about 5 students to 1 instructor where we would discuss and work through the material.

What you're suggesting is basically the same, but having recorded lectures.  Given that most of the lectures were non-interactive, it amounts to much the same thing.  In general, I found it a very successful approach.