I would recommend the firm tapes too, I first tried them out 12 years ago and have used them off and on during my weight loss struggle.
Qvc also sells the firm tapes (
www.qvc.com) and apparently if you buy the infomercial set from them, you get an extra tape.
The firm tapes are hard, but you can easily modify. My legs are short, so instead of using the full 14 inch step, i was the 10 inch? on exercises.