At 30 pages, this is the longest Player's Guide I've seen yet. The balance differs significantly from previous Player's Guides. Instead of being mostly advice about characters and how they link with the adventure path with a couple of extra rules thrown in, this is the opposite: there's a whole bunch of rules for ships and naval combat and the players get only a few pages.
The usual breakdown of why particular classes or races may be in the area, or what connections they may have to the adventure path, is pretty much skipped. There are vague backgrounds mentioned in the mostly mediocre traits but otherwise this section appears rushed and incomplete. This will be a major shortcoming for those players who wish to define their characters in terms of life in The Shackles. Likewise there is no overarching goal implied to aid party unity which will be even more important in a Chaotic leaning Adventure Path.
The rules for Naval Combat start simply, devolve, then end with over four pages about seige engines. The premise is good, the execution is standard and details are overly complicated. However, there is a highly useful page about spell effects at sea (though Fireball is listed under 'D' for Delayed Blast Fireball). There are also plenty of options and ideas for ships, with stats and modifiers for various types, and included are a ship character sheet and a page of ship counters. At about nine pages, this is a nice balance between complexity and options.
Overall, this is not a Player's Guide but a bunch of extra rules that look like they didn't have the room to be crammed in the module.