The author is a regular contributor to the SF Chronicle Newspaper, and her articles are always a treat. She has a great writing style and is extremely witty - this book is actually an entertaining read straight up even if you're not looking for a guide book. She "gets" San Francisco and passes it on to you.
Especially invaluable if you have friends/family coming to SF and you need to show off our little city by the bay, but can't for the life of you remember anything to show them, except for things starting with "Fish" and "Golden". Many chapters that customize a visit to SF for each visitor type - from that "interesting older aunt" to the "wornout by the kids couple". It's a lifesaver when you're expected to give someone the "SF Experience".