Crescent Moon is definitely my favorite Xinjiang place in Beijing. The chuan'r is particularly great, but all the food is delicious. The decor and hutong setting also add atmosphere to the dining experience.

I've never found the staff to be outright rude, but they can certainly be surly. I go there a lot and have often been served by the same waitress. Any attempt at a friendly "hello" has always been met with a cold blank stare however, so now I don't bother.

Still, if you can ignore the waitresses' icy demeanor, the food is great.