I have it, and I really enjoy it, but I like very authentic-feeling kickboxing without a lot of choreo or aerobics moves thrown in (à la Powerstrike). This is probably the least choreographed of Janis' kickboxing workouts (and I love it for that reason). She co-leads with Guillermo Gozmez, a black belt a couple of different disciplines who has excellent form and energy. I really enjoy his teaching style (he even uses Spanish once in a while for counting and for encouragement: "vamos"!)
It is an interval-type workout alternating kickboxing drills with weight work. The weight work kind of bugged me in the beginning, because they use very light weights, and the same weight throughout. You go from a lat raise to a shoulder exercise or a slow punch sequence with weights. I decided that this is really a cardio workout with some added weight work for key kickboxing areas (arms, shoulders), and not a full-fledged resistance workout, and it works better that way.