I have thought about starting this myself. I would like to know the same thing. I am getting tired of just walking, doing the eliptical, and just cardio. I am wanting a change in my workout routine.:ohwell:

I am new to the group so I see that you posted your question a long time ago. I don't know if you ever found an answer for yourself, but I'll post my answer anyway.
I do have P90X and it is a butt kicker. You will sweat like crazy and get your heart rate up. I like that the program has different degrees of difficulty or options for workouts. I have had to modify quite a bit of the exercises so that I can do them at my level, but over all I find it to be an effective workout.
Good luck!