Two good Chinese restaurants in Mountain View on Castro Street: Hangen Szechuan Restaurant and Hunan Chili. They are very close to each other and are virtual clones of each other. As for downsides: Hangen — The owners wife could use a visit to “charm school”; Hunan Chili: They try to get you to pay in cash, though nowhere does it say that they have a min charge to use the credit card. If you want to get around it, just say “I have no cash”. They’ll then accept your credit card!
If you visit either of these try the Mapo Tofu. If you like spicy food you’ll love this dish.