Almost great...
I purchased three pairs of these leggings, and kept 2—the Pebble and the bluish-grey limited edition color. I returned the Jet Black because it seemed like when they were on they were stretched and you could see some metallic-ish threads, and I didn't like that. Not exactly "Jet Black."
I really enjoy that these are mostly organic cotton and they get the job done. However, I was washing them on delicate and air drying and the top portion seemed to stretch and get loose and would fall down as I walked, leaving me with a saggy crotch. Constantly having to pull them up. I put them in the dryer on low once to see if they'd snap back, and they came out with a hole. Very unfortunate. As more brands are starting making cotton leggings, I will opt to try those.
I also wouldn't consider these "flattering" as they make my butt look flat. The only perk to these is simply the materials used, which is a significant consideration.