The cardio is really short in Timersaver, around 30 minutes, or even less. You'd probably be better off getting the full blown workouts (Step Blast/SJP and KPC/Legs&Glutes). I have the entire Body Blast series, including Timesaver, but I find I never ever use Timesaver. The Body Blast series has such great premixes for cardio, ranging from maybe 30 minutes up to about 90 mintues.
Timesaver is probably good, however, if you are new to Cathe and just want to try her out.
Shelbygirl