With Drizzt, the most famous drow, as the author, you'd expect this work to spend a lot of time detailing the drows and their culture. Not really so. Covered are 9 major races of the Underdark, drow as just one among them, and a mention for several lesser ones. The survival guide part in the book is quite literal survival guide, but the majority of the book is taken up by the city descriptions - as generic backdrops for adventures to take place in, with too many of them covered too fast to get into details or particular societal customs. As the name implies, it's a good sourcebook for an overview of the entire Forgotten Realms Underdark setting, but don't be fooled into expecting detail or depth on any particular single subject; that's not what this book is about.