These are absolutely my new favourite leggings; I got rid of all others and now want a second pair! They have stretch and compression without feeling squeezed in, and the high waist is fabulous, no rolling or sliding down or sagging throughout the day. Also, not itchy! Love them. They aren't fully opaque, which is my only wish for improvement. But I wear them under long tunics/dresses anyway, so doesn't bother me much.
I'm typically a small or medium in other brands, and went with a small here, and they fit perfectly. (I'm 5'5" with a long torso - 29" inseam, 29" waist, 35" hip, 135 lbs)