The dim sum is secondary to the baked goods. Actually, if you completely ignore the dim sum part of Kim Moon, that would best.
The baked goods are above average, especially for the downtown core area. Easily the best egg tarts south of highway 7.
They are also one of the few bakeries in the downtown area that carry common Hong Kong bakery staples such as butterfly cookies and neopolitan cakes (made from pastry dough and not bread).