This book needed more time in the oven, and it shows. It's a messy book, with a bunch of good things marred by a LOT of errors and ambiguous or poorly worded/confusing changes. It seems pretty clear that Paizo ran out of time to meet the print schedule. The lack of day 1 errata is particularly galling, though, as some of these problems would have been obvious for anyone who checked the book internally after it was sent to print. Expecting GMs and players to just figure these things out on their own is not at all a good experience, especially for a core book that should be getting the most attention.
The class updates are mostly good. Oracle is the glaring exception, where all the flavor and distinctive nature of the Mysteries and Curses was gutted in favor of something more generic. If you didn't like the class before, it probably works better for you now, but a significant number of Oracle characters that already existed are severely harmed by these changes, while Battle Oracles were basically broken and Life Oracles are now the worst healers of any Oracle despite the name. It's a crying shame what happened there. The class needed a tune-up, nota half-baked rewrite. (It's a great Multiclass Archetype for another class, though.)
A round or two of errata would help this book out tremendously to clean up a lot of the messy parts and the ambiguous or confusing items. But as it stands now, this isn't up to the standard I expect in terms of editing quality.
This book is fine as a standalone "facts about Riddleport" book. It does that pretty well.
The problem is that it's also the players guide for Second Darkness. It does that, for the first book of Second Darkness.
By book 3, Second Darkness is an entirely different adventure than the one the players guide talks about, to the point that the players guide is actively misleading about what the adventure is about and what kind of character you should make. If you make a character expecting to be doing morally grey stuff in Riddleport, you are in for a very rude surprise when the AP abandons all of that and changes tone and setting completely.
This is straight up the worst book I've ever played. Definitely a low point for Paizo. It's SUPER railroady. The Elves you're supposed to want to help are somehow even more unlikeable to the point that you get actively punished for helping them. Then you get led through a bunch of stuff to meet some even more unlikeable Elves that you're supposed to help despite them not wanting or deserving it.
You get forced into working with a demon, though she's frankly far more likable despite the inevitable and obvious betrayal when stuff happens that doesn't really need player involvement at all. This really felt like a book where stuff had to happen a certain way and so they just wrote that's what happens despite a lot of it making no real sense for the players to want to do.
I don't know if it gets better in book 6 because our campaign effectively ended due to this one.
A great thing about Foundry is that all the Bestaries are included out of the box. You're good to go right away. A less great thing is the lack of token art out of the box.
This pack fixes that lack, and the tokens are spectacular. They did a great job bringing the monsters to life and making them look nice.
You can do this all yourself if you put the time in, but mine never came out this nice and it's pretty time consuming to have to prep tokens for monsters constantly. At this price, this will pay for itself very quickly and is a must-have.