mspina
Cathlete
And now I understand why you called the X workouts your "light days" workouts. The program's focus is for building strength, not losing weight, so the cardio is structured accordingly. That said, you can get a GREAT workout from Plyo, once you get used to it. When you go REALLY deep into the moves, the intervals are incredible (I find them harder than Cathe, because there is absolutely NO choreography). The first time I did it though, I thought it was slightly less intense for the reasons you mentioned. I've grown to love it over time though.
m.
m.