Chang's Has being in my top list of Dim Sum restaurants in the valley, I've been coming here since 2002 and time and time again I've had a great eating experience. One thing you want to make sure to do is to get there b4 the lunch rush and make sure to always ask for the fresh dim sum on the cart.
Some folks have told me that the've had a hard time eating at this place due to the language barrier with the servers, I myself have always make sure to treat all of them with a smile and always w a thank you and my experiences have always being great.