I have been doing the body blast rotation using the Intensity Series for about 5 weeks now. I absolutely love it! I have not made any changes to my diet but have noticed recently that I have put on 1-2 pounds. I try to eat clean, but I have to have chocolate in the afternoon, or I will cease to exist! And I've been trying to eat more protein. Anyway, my pants are looser now, so I am assuming that I have replaced some fat with muscle which would account for the slight weight gain. And I have really made some strength gains, which I feel so good about, with even more muscle definition. And I can do all the push-ups on my toes, which I have never done before. Yea!!!!!! I have not really used the CTX series in a formal rotation so I'm sorry I can't give you a comparison of the two. I did a lot of mixing and matching, mostly with Bodymax, Circuit Max, MIC, IMax and MIS. While doing this I was able to maintain my fitness level, and was where I wanted to be weight wise. I do sometimes use the cardio sections in CTX before doing a strength workout. Hope this helps.
Nancy