These are good leggings for fashion uses, but I would not use them for exercise or dance because they are see-through in the butt when you bend over. I like the weight of the leggings - it's a lot thicker than tights or jersey leggings - but does not add any bulk.  They offer some support, but they are not like control top or girdle leggings for slimming purposes. I am 5'10" and 145 lbs and I got the size Large, which is perfect except that the cuffs end about 1-2" above my ankle bones. I would prefer these leggings to be longer. I haven't owned these very long, but they don't seem like they will get baggy knees quickly, though all cotton blend leggings do wear out with time.