Just got my Ninja suit today! I love it. I thought it was going to be more of a shiny spandex material, but it's not at all, it's a really nice soft material with a stretch.
I ordered size large and it fits perfect. I am 5'6" and usually wear a size 12 in pants. The crotch isn't saggy at all, and I have pretty short legs. I read the review that suggested sizing down and I agree, I would usually have ordered an XL but I am glad I got the Large.