I checked the first one out from the library and tried it at one point to see if I was interested in buying it--decided against buying it. For me at least, the workout wasn't intense enough to be aerobic, and the exercises and instructions on the DVD weren't enough for me to use it as a supplement to the weekly ballet class that I already take. All the form pointers that I needed were in the descriptions in the book, and I just couldn't try to workout and follow the tape and read at the same time. I do know, however, that some people record the instructions on the book onto a tape and then listen to that tape while watching the video. Anyhow, for me at least, it wasn't worth it--I got a good warm up and stretch from it, but that was it. Amazon.com has some more thorough customer reviews, though.