The reviews were pretty decent on these so right off the bat I bought two two packs of the black.  They are really comfortable. They are a nice length and are pretty stretchy.  I got these to wear to sleep under large t-shirts and night gowns.  They are a bit sheer when stretched so not sure how they would hold up during workouts.  They also roll up a bit around the thighs but that really can't be helped I suppose. One size option doesn't seem to be able to fit all. I weigh 135 and like I said these are a nice fit for me.