I was new to Pathfinder, and I wasn't sure what to buy, but my local gaming store had this book, and I needed a city to set my game in. I was glad I picked this up! Absalom's history dove-tails with that of the Inner Sea as a whole, and reading the history section gave me an excellent feel for the state of the world.
Much of the work in this book is of the finest sort I've seen in an RPG, and the art is phenomenal, walking the fine line between realistic and fantastic with style.
If you're looking for a book full of crunchy statistics, spells and feats, this isn't it. If you want to get your feet wet in the setting of Golarion's Inner Sea, this is an excellent place to start and ultimately a key reference in any Inner Sea campaign, especially those that will take place within the city.