Although I really enjoyed Bridge of Birds, I thought that some of the magic had gone with The Story of the Stone. The motivation of the characters in Stone is shallow, and they're acting like detectives in a rather simplified story compared to the predecessor. The emotional connection of Number Ten Ox to the story is missing. There isn't the personal link that drove the characters to every crazy situation and mishap. There is less inspiration.
The secondary characters weren't so full of personality. Even the characters that end up being very important, never caught my eye until the last few pages. Most of the scenes take place in the same area, there is less travel.
The expedition into Hell was confusing and seemed rather unnecessary, and it drove the plot out farther.
I was disappointed by Stone, and I don't think I am going to read the next one, as the reviews for that say it is even weaker than this one.