For me, the cardio sections in HSC don't have as much impact as the ones in BC. I'm not saying HSC cardio is "easier", only that it has less impact. And that, for me, means HSC cardio is better for my knees. I think only 2 sections are done on the step; the rest are done on the floor.
Do you have HSTA? There are many similarities between HSC and HSTA. I've read others' posts about HSC being more difficult. Both are tough workouts to me. HSC, thank goodness, doesn't have as many leg presses...
Pinky