The best time to go is also the worst time to go--during Chinese New Year. They have special dishes just for the occasion, and it's also when their crab legs are the freshest. The place is usually PACKED and we've waited more than two hours before being seated. Insane.
In general, their food, as well as the selection, is pretty good. I brought a friend here who recently visited China and she was impressed with how authentic the food tasted.