This is not an appropriate reader for me right now. It is very boring, things happen very slowly. Everything must be explained, and everybody must be in the know, or there is a good reason not to tell him or her. It is a very childish book. You are not willing to read the next chapter; you only want the book would be over.
Nevertheless, I have found it very useful for learning English. There are a lot of expressions, phrasal verbs, repeated every now and then, so it is helpful to learn them.
The language sounds very natural.