I received a review copy of this book, and reviewed it here.
Gods and Icons does a great job of expanding the world of 13th Age to help the GM with worldbuilding and the characters with options for the gods they follow. The additional tables to roll on for magic items seem like they could be a godsend. If you're looking to expand your game, this is a great place to start. The Player's Companion includes much of the same information as the main book, except for the magic items and some locations.