The nice thing about Sun Sai Gai is that it is only slightly giving you the feeling you get when you are right out front, jostling with all the tourists and hawkers. The crowd inside is mixed with Chinese people and tourists who think they are braving it.
I really like the unofficial uniforms here, short sleeve button-up shirts with the maroon vest over it. The servers are efficient (and a bit gruff) and give the place a further sense of what it is: a diner. But it's really no better or worse than most Cantonese restaurants in Chinatown, and it is worth it to come for their signature dish.
The barbecued pig with skin over rice ($5.50, below) is certainly not going to blow you away, but it is a quick and simple lunch that is really comfortable, and completely filling. The pork is lightly seasoned with a very subtle crispiness to the skin, served on rice, and covered in a small amount of gravy for good measure.
The rest of the menu is no different from many restaurants in the area, so it is not worth covering more, come here for a quick dish and get going with the rest of your afternoon.