The zipper in the front is real boon to getting a thing like this on.  The Large is a little big for me and I have ordered a Medium, but have decided to keep both.  The Medium is tight and makes me very shapely, but can be a little uncomfortable, and the Large works too but is a little looser.  Both of them seem long in the body and the zipper comes up a little high for me, but I just leave it open a little and that works.  It really pushes the bosom up from the sides towards the middle, kinda like a pushup bra.  My only complaint is that the area right below the zipper, just above the hooks for the crotch is coming apart on both sizes.  That's right where you grab it to open the hooks or close them, and I've put my finger through the seam on both of them.  I plan to sew it up, but that's it so far.