Anyway even only being able to do 10 - 30 minutes of the workout (and I did this every day ) I still found in 2 weeks my tummy was definitely tighter, arms more defined, I had more stamina and energy and by the end of 14 days had lost 4 kilos (approx 8 pounds) which I thought was pretty good.
You will not know if it will work for you until you try, but I have found if you are not active, the full 40 minutes to 1 hr can be a bit much so maybe start slow.
I guess they all work you just need to do them daily the Fat Blaster is more intense but I'm just a kid and I did the 40 minute cardio everyday and its not that bad once you get used to it.