First of all it´s been there since 1974. El Buda Feliz is not a restaurant but an institution. They made a renovation, the restaurant is very nicely decorated (the bathroom deserves a tip for itself haha) and the food improved recently also with a change in the menu.
It has a nice "terraza" in Calle Tudescos, 20 meters from Gran Via. If you want to eat true Chinese food or drink a cold beer in a nice open-air environment, this is great. You will be pretty near everything that Gran Via has to offer but will be able to have your caña peacefully.
The transparent noodles are AMAZING.