London got thousands of Chinese restaurants. You could find some restaurants are high end market like Yauatcha and Hakkasan. However, you also can find some are more local, but food is ok. It is not bad, but nothing special.
I discovered Pearl Liang in Paddington few months ago and had been returned back to it since I had tried it. Good interior of the restaurant with high standard food and dim sum. It is very friendly environment and price is reasonable. I could not find better dim sum in town. Highly recommended. 5 out of 5!