Yep, I do them, and I LOVE them!! I have the new Body Sculpting System, with the fanny lifter, and also a couple of other newer tapes that they have put out. I agree with dreaming that the older tapes are supposed to be the hardest, I haven't done any, but I hear they really kick your butt. But the ones I have kick butt, too! I've been using them since mid-Sept. and I have gone down a dress size and lost 7 lbs. so far, which might not seem like a lot, but I've gained a lot of muscle and lost that layer of fat (well, a lot of it, lol!) I had lost 30 lbs. over the last couple of years, and I had come to that dreaded plataeu, but with the Firm, I've broken through it. I was only using a treadmill for exercise before, now I do both.
dreaming is also correct that you do need to commit to doing it at least 4 times a week, up to an hour or so of exercise. But, you will see results. On their website, their are message boards (you have to pay to use them) with lots of support and the actual instructors on the videos are the moderators, they have auditoriums and chats with them to answer questions, and they also answer your questions on the boards. I find it really helpful and informative.
As far as the rotations go, I've made up my own with the videos I have, but on their boards, there is a whole board devoted to rotations, with an instructor to help you, challenge you etc. You rotate because you want to "shock" your body/ muscles, and not overuse them, so your rotate btwn cardio, sculpt and cardio + sculpt tapes.
I hope this is helpful, feel free to PM me it you have any questions!!