As a lover of geography courses, this book hits all the right notes. Qadira comes across as a real place, with concise but well thought out emphasis put on the factors (cultural/economic/geographic/etc) that make a nation and its peoples what they are. There are also frequent and interesting glimpses of Kelesh and Casmaron, with particular emphasis on how Qadira's status as an Inner Sea nation affects its relationship to the greater empire. Amongst all of this excellent information lie plenty of adventure hooks and rules options to help Qadira come alive during a game. The ashiftah battle witch is a simply written but super flavorful archetype (for real check it out), and the genie-touched horses are a clear fit. The patronage system adds some structure to help you convey what for a GM could be a very important but difficult to navigate aspect of Qadiran culture.
Basically, this book really adds to the Inner Sea and Golarion as a whole. You should buy it!