After Step Heat, I would move onto Step Jam, (which is pretty long, but fun to do), Step Works (my favorite non-interval Cathe step tape) or Power Max, another fun one. Re Interval Max II, Imax II is higher in intensity than Intense Moves but it does have somewhat tricky choreography (ricochets, figure 8's, insoles around the world, and up and backs). If you learn these moves in older Cathe workouts, you should be fine. Have you ever thought about getting the original Imax? It is more intense than Imax II, but less tricky in terms of choreography. Most of the step routines have you facing the tv the entire time, whereas in Imax II, she has you with your back toward the tv a bit. I like them both, but the original Imax wins out in terms of intensity and I just feel sheer joy every time I complete it!