I have read the book and liked it very much.. I write drivers and applications on routers of a reputed company and encounter the problems mentioned in the book almost on a day-to-day basis. The algorithms and case studies in book are really good and they are valid in the present state of network devices. I would recommend this book any engineer working on networking devices and applications.
In addition, the products George Varghese's research work were implemented by different network device manufactures including Cisco, Juniper, Procket etc. Lot of research papers can be found in his homepage.