Cathe does great cardio but so does the Firm. They are DIFFERENT. I use both for cardio. It's called cross training.
Other great Firm cardio workouts would be Super Cardio, Cardio Burn, Maximum Cardio, Cardio Step Mix. Tough Tapes and Standing Legs also give a good cardio as well as strength workout.
I have been using the Firm tapes now for @4-5 years. I was just recently introduced to Cathe. While I believe Cathe tapes are harder and more productive I don't always have the time to finish and wind up skipping something. The Firm combines Cardio and weight all through out the workout so and the end of 60 minutes you have worked everything. Try the Firm they are worth it