This place is good. Really good. Ka Mei is the only authentic Hong Kong cuisine in Pittsburgh as far as I know.
The place has two menus, the authentic menu and the Americanized Chinese menu. I highly encourage you to pick from the Hong Kong menu for the full experience. The food here is clean, and not at all greasy as you might encounter in Oakland. And by the way, the portions are huge! It's definitely a place you want to go with all of your friends, and you'll still probably have leftovers for tomorrow's lunch.
My personal favourite item on the menu is the Salted Squid. When you eat the pieces of deliciously battered squid, make sure to get a piece of jalepeno pepper with it for maximum flavour! I also want to say that their shrimp wonton soup is really, really good. The broth is clean, not overly salty, and so very tasty.
Ka Mei is definitely favourite.