My wife and I have made the 35 miles sojourn east to Hong Kong Palace in Rowland Heights several times in the last few months for dim sum and have been very pleased. On the way there we had noticed Guangzhou Palace on Nogales and after hearing from a friend that it was quite good, thought we'd try it.
We went this past Sunday. It was very busy but it was decidedly sub-par. Most of the dishes were room temperature or even cold, a first in my experience. The selection was considerably smaller than most other large local restaurants and to top it off, the staff was unbearably rude - the rudest we've ever encountered in LA.
I wouldn't recommend it. Hong Kong Palace down the street however, is excellent.