This scenario follows the ongoing story of the Scarab Sage faction. It's thoroughly enjoyable, and I highly recommend that anyone (but particular Scarab Sages) give it a shot.
Combat-wise, it's challenging without being ridiculous. When I played, we had a dedicated striker in the party who was able to absolutely ream many of our opponents. Despite this, I and several others nearly died in a particular encounter due to the difficulty of the creature we were fighting. It was exciting, but at no point did I feel that our opponents were overpowered.
Story-wise, it's an excellent discovery-style adventure. There is not a lot of negotiation (though where it does happen, it works very well, with tried-and-true mechanics). However, there is a *lot* of story, background, and setting to discover. In some cases this involves simple rolls. In others, it involves more complex mechanics that, quite frankly, are extremely well thought-out. Unlike previous versions of this particular "kind" of skill roll, the one here both (a) makes sense, and (b) doesn't unnecessarily prolong the adventure.
The story culminates in a choice that actually feels like a choice. Unlike other scenarios where choices are made, the choice here presents an honest-to-god moral dilemma for the players, particularly if you have a wide variety of alignments.
Suffice it to say, this adventure is an excellent one. It's absolutely worth playing, and was probably the most enjoyable adventure I've played in a few months!
This scenario brings together a number of threads from previous scenarios, including previous specials. I played it at PaizoCon 2016, and thoroughly enjoyed it.
Combat-wise, I would say it is of above-average difficulty and definitely high quality. There is one combat in particular that even an experienced and prepared party will struggle with (in my case, my character was only saved by the timely use of my endurance brand!). Equally importantly, there are a number of combats whose ease depends *heavily* on what the players do. If the players play carefully and smartly, they'll do very well. If not, they could very quickly become overwhelmed. So overall, the combat aspect of this was *very* enjoyable and challenging.
The social aspect has some good chance for what I think of as "quirky" roleplaying, in which you roleplay not so much to gain advantage but to enjoy the setting. It's fun, but it gets a little repetitive.
There are a few mechanical issues with the scenario, particularly with regards to how information is apportioned to the player. I won't go into detail here, but it's very easy to miss a rather nice story element if your GM isn't very flexible (due to how the adventure is written). It's not a huge deal, but as someone who really likes the story aspect of scenarios, it's enough for me to (in addition to the repetitive social aspect) ding this scenario a star.
Overall, I'd highly recommend it. It definitely ranks with the higher quality Season 7s.