Food: Rubbery, dry and uninspiring dumplings. Rude service. Very overpriced beers (that you have to beg for).
Performance: well rehearsed, but not suited to a western standard of good entertainment. If you're expecting to be blown away, best avoid. Lots of dancing in cheap (and stained) costumes.
I can't complain too much as his was included on a tour. but this definitely doesn't deserve to be rated as a best restaurant of Xian!