Firstly, I'm 5'7, 159 pounds.  I wanted to just smooth out some post baby belly.  I'm not fat by any means.  This undergarment was far too short for my average torso, to the point where it pulled significantly in the crotch.  It does not sit as low as the image would have you believe.  The adjustable hooks didn't help lengthen it too much.
Getting it on was literally painful.  It was so small (I ordered the medium according to the size chart) I had to fight to get it all the way up.  The fabric did not stretch the 2nd time I wore it either.  I did get it up, but not without difficulty.
That being said, it never rolled down, sits right under the bra line.  It was tight on the torso and did smooth out the front in clothes.  The back made a crease where it was displacing all the skin/fat/whatever.  It didn't matter how high up it was pulled in the back, it creased at the waist line area.  It did a basically fine job, not great, wasn't comfortable at all, but it was less expensive than Spanx.  Next time, I'll go with Spanx.