I bought a small/medium for my 100lb 4th grader who according to the size chart is rated for up to 150lbs and when we received the tights they were for a small child a size 4-7.
Pros
We use them for a dance recital and they work great.
Cons
These tights are only available in one color, jazz tan, which may not go with all outfits or dancewear.