Thanks for your responses. I think I'm gonna try out the Simply Step and see how I like that one. I have mastered a few of Cathe's step tapes that aren't to tough, but some of them I get totally lost. I am advanced cardio wise, but not good with intricate steps. I can do I-MAX, MIC, Step Fit, Step Heat, etc., but with I-MAX 3, I have started it several times and cannot get it down! It sounds like Simply Step is tough enough cardio but the step work isn't complicated, which is what I need.