I have been diagnosed with Fibromyalgia after a year of dealing with injuries sustained from a car accident and gained a bunch of weight thanks to over-eating and drinking. With the injuries I have, laying on the floor to do sit-ups is impossible. It hurts my neck and upper back way too much and causes more strains and pains than good small burns. So I took a chance and hoped for the best with the equipment.
Hauling it into my car was not too bad, it slide into the trunk and I was able to get the box through my house with little problems. Setting it up was confusing with the directions and labels on the bars. The handle bars that are by your hips when you sit have yet to be of any use for me except to manuever in and out of the chair. After setting it up and training myself to disable it with out looking at the instructions, I figured out how it folds together and will truly slide under a bed frame or futon or in a closet. You do have to fully take the handle bars out which is annoying since they really are not useful in the full setup.
Doing the sit ups was pretty easy as far as movement and pressure against my back and neck go. Little use of my neck and upper back making it swift and painless. You can make the mistake of using arm muscle too much to sit up instead of focusing on the abdominal region but when I slip my hands under the arm strap instead of the soft arm handles, forcing more of a work out for my stomach. The only painful part is after 25 sit-ups, the bar where my knees lay starts to bump against behind my knees and makes them sore against the hard metal.
I have yet to receive "Amazing sexy abs" but have noticed the stomach slowly shrinking and I do believe it is possible to shrink with proper eating and other exercise. I would recommend against this model but would look in to the newer version because if you do have neck/back problems, you can get results with out damaging yourself.