I use them quite often, unless we have guests over O.o
I'm not sure about in China, but in Japan at least there are a few things to keep in mind:
Hold them near the end. Not the end that touches the food, the other one :3 This kind of helps when eating things like rice or noodles, and looks awesome
Etiquette, like don't point at things with them and don't stick them straight in your bowl. These things are all over the internet though, just google chopstick etiquette
It really helps to not stir your rice around, as then the grains unstick and you can't get the last ones. And yes, it is slightly rude not to eat the last few grains :3
They take some getting used to, but I find they are no slower than a knife and fork
Much cooler as well