Hi Mandi,
I am not a great stepper but I do Cathe's step - only. This is what I have managed so far:
Low Impact Circuit is really fun and pretty easy to master - great music
Imax 2 - same - great music and enduring
Cardio & Weights - same - great music - intermediate
Athletic Training - I love drills so this is a great one for me and enduring
Athletic Step - was a bit tricky but once i tried it - I got it quickly
Intensity - I grasped the steps quickly except that last combo - still haven't bothered to master it
Lowmax is tough for me - still don't know it, same with Imax 3 and the step workouts from 4DS and LIS. I need to spend some time with them and haven't
CTX - no real problems for me and like it
Step Jump & Pump - took me a few tries but I got it - great music
Body Max2 - that took me many many attempts but I started with this one so that probably wasn't the best idea - great music
Step Blast - I've got some of the combo's down - not all - great music
Interval Max - Love that one and found it straight forward
Body Max - step portion was easy for me to learn too - but by no means easy
That's all I've tried. I hope this helps.