Finally reached chapter 7 of John T. Moy: "Ospf: Anatomy of an Internet Routing Protocol" which concludes everything on basic OSPF theory.
Well... as an author, JT Moy could certainly improve. These are the only two values... with the exception of... is not a sentence which will earn him the Pulitzer Prize. Then again, he took the effort to present well worked out examples. It would have been even better if all those diagrams would stick more closely to the pages referring to them. This book is indeed a "page turner".
All in all, the book is OK. It certainly is a gentle introduction into the subject matter. And the look back into the time of 1997 with its state of the art network / Internet-wise is certainly refreshing. 40.000 DFZ routes! Frame relay!