I can't say that Intensity Series will be better because I haven't done it, but I have every Cathe DVD and have yet to be disappointed. She simply does not make poor/ineffective workouts. With that said, CTX is SOOOOOOO versatile. You can do the cardio on days you only have 30 min. You can combine 2 cardios on days you have more time. You can do one body part of weight work per day or do them all at once. And Leaner Legs is her toughest lower body tape (IMO). I really like CTX and use a component of it in every rotation I do. Have fun. P.S. You will eventually own them all, the question is, which order do you want to purchase them in. If you order them all now, you save on shipping!!!