The PCs can now choose to ally with one of five rival factions from the Aspis Consortium, the Shackles Pirates, the Pathfinder Society, the Red Mantis or the Sargavan Government.
This is one aspect of the AP that I really like. Too often it is the PCs versus 1 BBG or a Horde of Monsters. Now you have several diverse factions competing for the same goal as the PCs. I am interest to see what factions your PCs join and how you plan to use them in your Campaign.