Roxie,
This workout was my intro to kickboxing back in the day! As to someone's question as to why do Kathy, when there's Cathe? The Kathy Smith video has EXCELLENT form pointers, courtesy of Keith Cooke. If you haven't done a lot of kickboxing, or wonder about your form on punches, kicks etc., it's great for keeping your workouts safe and effective. I still really like this workout for lighter days. There's no dread factor and not much high impact. You get a good intermediate level workout and if you follow Keith's clear, easy to understand instructions, you learn to avoid common KB related injuries during any KB workout.
Yes, Cathe is much more intense, and very fun, but she's geared to experienced kickboxers. Lastly, Cathe's form on her earlier workouts (Cardio Kicks, CTX KB) is not as strong as it is in KPC, KM and 4DS so you have to keep that in mind when you're doing the early ones.
One thing you gotta love about Kathy Smith is she brings in the experts when she ventures into new territory (kickboxing, boxing, yoga). HTH!
Jonahnah
Chocolate IS the answer, regardless of the question.