I haven't done P90X but I hear it's great. It's definitely not my type of thing though. The workouts are too long for me (an hour each, I think). I do Insanity and I love it. The workouts are a little shorter and I don't need any equipment, which is great for me. I'm doing a combo of Insanity and ChaLEAN Extreme. This works for me because for the most part I can get my workout done in 40 minutes or less and I feel like I got my butt kicked!!