The first 25 minutes of Athletic Training is done on the step and equals the Intensity Step portion IMHO. You are working on an 8 to 10 inch step however.
Afterburn is like the HIIT portion of Intensity-except low impact and harder! Cardio Supersets is a slightly less intense version of Afterburn. I don't think you'll be disappointed in any of these if you want a tough workout.
Beth