Our medium-sized Mutton Fat Jade Porcelain cup is of a design called a 不倒杯, meaning "no turn over cup." It has the entertaining quality of being weighted such that it, after being tipped over, will right itself. It won't save your tea from spilling, but it does give a charming element to this smooth, soft-textured cup. The overall shape is bell-like and tapers from a thick wall to a thin lip, making it very pleasant to sip from.
These behave pretty much as advertised. The texture is very nice, the capacity makes them very practical, and they have a reassuring heft to them.