Ive been to blue lagoon twice now, one for dimsum and one for dinner so ill write about both experiences.
Walking in you'll notice its brightly lit and very spacious in comparison to alot of other dimsum places, and they had a great tea selection, i usually go with the chamomile. The dim sum is average with the stand fare youd expect at most dimsum places. The dish that really stood out compared to other restaurants is the durian stickrice! Id come back just for that. Its also cheap dimsum if you come early on weekdays.
I also had a great seafood dinner with my family, we ordered lobster, peking duck, and a few vegetable dishes. In comparison to uptown seafood places(omei, fishermans) id give this a 8/10 the claw pieces were a bit salty but the rest of the lobster (cooked three ways) was enjoyable. The dessert that came in the end was lacking and left much to be desired.. sugar syrup and jelly?? I was hoping for atleast a redbean dessert thats standard in most chinese restaurants.
Overall id just come back for Dimsum, but if you dont want to drive all the way uptown then this resto will do.