I love these leggings! I recommend ordering one size up. I'm usually a size 2-4 petite in pants and I ordered the Medium just in case, which fit perfectly. They're comfortable, they stay put through any type of exercise, they pass the squat test, and they're fine for lounging or going out. I love the pockets and the waistband flattens your tummy without being too tight. Although the material is of medium thickness, you can still see underwear lines unless you wear seamless panties.
These leggings are of really good quality, and if you're petite like I am, you'll appreciate the shorter 7/8 length, which goes down to my ankles. So they're almost full length on me, which is much better than leggings that are too long. I would definitely recommend these yoga leggings to others; they're one of the best I've ever owned!