I needed something because I was in a bind for a bridesmaid dress.. it was WAY too short. This slip seemed a little pricey when I purchased it, but when I got it I understood. The quality is really great. It's super stretchy but still opaque, which for us plus size girls is hard to find. It doesn't get that weird girdle shiny-ness that I'm used to either, so that's great!
It doesn't hold you in, but it's a really smooth garment. I've got a chiffon dress I'm putting over it, and because of the way it's made, it's adjustable in length. If you need it shorter, pull it up to the bust. Longer, pull it down to the hips.
If you can get away with it, it could be a super cute skirt on its own.