well, it really depends on your perception and what you think you will get out of it. The device is not intended to make an overweight user gain six pack abs. it is meant to tone core muscles in a very minor way. your best bet to get six pack abs is to get on a really strict diet, and do a bunch of intense cardio. there is absolutely no machine that will do the work for you. Just remember this one rule:
if it is easy and comfortable, your not going to gain anything out of it
aka
no pain, no gain
don't let anybody tell you otherwise. you NEED to work for the healthy body that you want. its not going to happen over night.
good luck