This book is essential to Vampire storytellers. I would call it the single best VtR sourcebook, and among the best products in the new World of Darkness at large. I'll try to tell you why without writing an essay.
This book is, obviously, about the city, which is at the heart of any Vampire game. It offers many city-building tools, including: suggestions for mood, considerations for creation of princes, plug-and-play people and locations, means of establishing and clarifying Kindred politics in a city, and new systems for portraying vampiric feudalism and territorial division.
A few highlights: "Broadening Virtue and Vice" is helpful to players, suggesting some overlooked ways of portraying one's Virtue/Vice. "Ambience and Attitude" actually gives optional systems for modifying Mental, Social, and Physical activities according to the atmosphere of a setting, and means of changing that ambience. As mentioned above, the book also offers many Districts and Sites, making it easy to go from one end of the city to the other and still have an idea of the new locale ready. Similarly, a myriad of supporting cast are presented in short entries, and can be combined with a companion list of character motivations to easily populate your settings with tasty mortals (and their accompanying entanglements). There's also a choose-your-own-adventure-like helper section for the Foot Chase mechanic, which adds some variety beyond rolling Stamina and Athletics. Other highlights for crunch people include Merits related to Kindred politics and vassalage, as well as cool Merits and pools for dealing with Kindred graffiti as a communication tool (which is a personal favorite of mine).
If you're running any WoD game in a city setting, especially Vampire, you'll be happy you picked up this book.