I bought these tights for my beginning ballet class and they have been great. They are very soft and I like how they 'transition'. My only issue is that the back of the waist band is a little prickly, but I just turn it over and it's fine. I didn't have any issues with sizing. I got the small/medium size and I'm 5'3" and 115 lbs. I would definitely recommend these tights, especially if you don't have time to change out of them after class like I do, since I have another class on the other side of campus right after ballet.

Update: I've been using these tights for over two months now and still love them, plus the issue with the back of the waist band resolved itself after a couple washings.