Okay, so I just finished reading through the third part of the Mummy's Mask adventure path from Paizo Publishing, entitled Shifting Sands. This book has a great mix of adventuring, including in-depth researching ancient information, role-playing with important NPCs, a camel chariot race, dungeoneering, and sandbox exploring in the desert.
For the researching they have an interesting mechanic which helps reflect the time and work involved in doing research in an extensive set of archives. Each library has a Complexity rating (the DC you need to roll against) and Knowledge Points (KP), which work like Hit Points. Researchers get one skill check per day. Each success reduces the KP by a certain amount based on class. For instance, Bards reduce it by 1d12 + Intelligence modifier. KP are set in multiples of 5 and for each 5 points it is reduced the researchers learn a bit more information. At first the information learned is more general, but with each level reached it becomes more specific and valuable.
For the chariot race a nice flowchart or track of challenges is provided. I like that it provides all the key information needed by the GM while leaving room for improvisation by GM and players. I got the impression that this track is similar to how Paizo's chase card decks work. (Those decks are on my wish list, BTW.)
The pdf version comes with the usual separate map pdf where you can turn notations and grids on and off. I really like these--I've been wanting maps like these for many years. These make it easy to print out plain versions as handouts or to add different notations to use the maps in your own adventures. One omission is that the final encounter area, Chisisek's Tomb, was not included in this map pdf.
The two powerful NPCs the players will have to interact with to get access to the various research archives and libraries both get full write-ups. The seven new magic item treasures are all very cool and most have a strong Egyptian theme to them.
The book also has a great section on the city of Tephu with a good map. This is extremely useful not only for the early part of this adventure but also for any adventure. Since the city is famed for harvesting the papyrus reeds in its vicinity and making papyrus there is a short "equipment" section on special papyrus types for magical and mundane uses.
Then there's a section on the various types of mummification (not just the Egyptian method) as taken from real-world examples. This section also includes a bunch of abilities, feats, and spells for variant mummies to keep the players guessing.
The book also has the next installment in the included Pathfinder Journal fiction story to accompany the adventure. I wasn't thrilled with this installment, but as with the previous two it includes extra bits useful for the adventure. In this case there is a map/sketch of a caravan encampment and a map of a papyrus workshop. I should perhaps say here that I was not at first happy with Paizo's inclusion of fiction in their adventure path books. However, I am liking this new approach of tying the story more closely to the adventure and including some "gamey" bits like maps.
At the very back is the usual section on monsters. Overall I wasn't thrilled by the entries here, except for several types of mummified animal which will be very handy for stocking tombs.
Bottom Line: I liked it and am glad I bought it.