So, Ultimate Intrigue took a while for me to come to a complete opinion on.
The Vigilante class introduced in this book is, in my opinion, easily the best non-spellcasting class Paizo has ever created. It breaks up its social options and combat options in such a way that you have a great character able to participate in all areas of the game without having to choose whether you want to be competent in combat or in the myriad other facets of the game like exploration, social encounters, etc. It has deep and well-designed talents that allow you to pick any of a variety of different ways to participate in combat, with or without weapons, and numerous tools for allowing players to influence the story with safe houses, contacts, and more.
At PAX West 2016 I had the opportunity to visit Paizo's Pathfinder demo area and play their pregenerated vigilante character. I honestly didn't expect it to go terribly well; after all, the vigilante is a class built around balancing two identities and moving between different social strata, so you'd think that this would require a more controlled environment where you know the other players in advance and have time to plan out how your character fits into the game world with your GM ahead of time, right? Turns out, I was wrong. The vigilante class is well-crafted enough that even while playing a 1st level pregen I was able to easily deal with situations in and out of combat, and it took me about 60 seconds of conversation to establish with the group that I had a secret identity they were privy to and might need them to cover for my character from time to time if he needed to swap identities. It didn't hurt matters that the only downside to anyone learning a vigilante's secret identity is that, well, they know his or her secret identity. You can go all Tony Stark if you want, announce that you are Iron Man, and carry on as normal. Very few of the vigilante's abilities actually require you to maintain truly secret identities, and the only real hit you take is that you're a bit easier to find by magical means (though even this can be addressed with clever use of the Safe House Social Talent).
The book also elaborates on the intent behind numerous spells that often prove problematic for GMs in games where they want to have a focus on gritty investigation of mystery, such as the various detect spells, speak with dead, etc.
I think my biggest disappointments with the book, and the reason I can't give it 5 stars, lie in the feats and archetypes. I'll start with the feats, and a bit about why I see most of them as representative of missed opportunities.
To start with, Pathfinder's skill system is heavily dated. When Paizo brought it over from 3.5, they combined a few extraneous skills, but otherwise did little to update things, meaning the core area of the rules covering everything in the game that isn't casting spells or hitting things is now well over a decade old and out of date. Several skills don't even actually work, or work well, as written, have interactions you're just supposed to kind of assume or make up (Ride and Handle Animal are a mess, Stealth requires one to check out FAQs and blog posts online to use as intended, Bluff and Diplomacy have more than a few vague areas and inconsistencies, etc.), so what better book to address, update, and expand these core components of the game than a book about playing skill and intrigue heavy campaigns? Unfortunately, Paizo chose not to go that route, instead relying on feats to stretch skills over their gaps and issues, leading to many of the feats in the this book providing skill uses that I've seen GMs at hundreds of tables houserule as basic functions of those skills to begin with. Instead of formalizing intuitive uses of existing skills into their basic function, they added a feat tax to allow characters to do things many people already thought they could do. While there is a section in the book going over several of the vague areas in a few key skills, these are primarily common sense clarifications instead of the full address the skills could have used.
The archetypes, like many Paizo hardcovers, are all over the place. Some of them are interesting and dynamic, like the Masked Performer bard archetype, some show an attempt at embodying a cool and modern concept but fail to achieve that concept in the actual execution, like the Magical Child vigilante archetype, and some are just plain bad, so obviously terribly designed that you almost wonder if the person who wrote them has ever actually played Pathfinder, like the Brute vigilante archetype.
Now, don't let the above wall of negativity mislead you; there is a lot of great stuff in this book, including perhaps the most inspired and well-crafted class Paizo has ever produced, a class that introduces really interesting design concepts, plays with components of the class chassis we haven't seen classes treat as quite so malleable before, and is a genuinely fun and interesting class to play in and of itself. Despite many of the feats ranging from useless to frustrating, there are still quite a few that are interesting and viable, and while the archetypes are very hit or miss, that's generally true of Paizo books in general and probably shouldn't be held against this one in particular.
My final verdict on Ultimate Intrigue is a strong recommendation to pick it up, if for no other reason than to add the Vigilante class to your game (though there definitely are other reasons to add this book to your collection).
