The Good:
-Setting: The setting is a good break from the standard Pathfinder module: the obvious being in that it doesn't take place in one of the typical Inner Sea countries.
However, this divergence is obvious in minor ways as well. For one, I couldn't find a single Lovecraft reference, and while the model evoked feelings of Indiana Jones and the Temple of Doom, it was clearly designed with the intent of having each encounter be different from the standard fare.
This alone was promising, and one of my favorite parts running (and playing through) the adventure.
-Challenge: There seems to be a lot of complaint about the level of difficulty in the module. However, my party found Cult of the Ebon Destroyers to be perfect. It's a solid bit harder than your typical adventure, I won't deny that. But it isn't the party destroyer people are saying it is provided your party acts with a reasonable degree of tactical knowledge.
The Bad:
-At times, some of the enemy tactics don't really make sense, particularly when its a group of "mook" enemies opposed to the BBEGs, in that they have reason to work together but choose to fight one wave at a time. This is easily rectified by sending in larger groups and reducing the total number of foes in a locale.
-At times, the players were left with only one avenue to reach the next plot point. As a GM, I worked with them to basically use reasonable progression to get to the next stage, although I would have preferred fewer individual hunts for information in favor of a more connected series of events.
-Some enemies can die before their slated final encounter, without a real clear analogue on who should replace them.
-As a GM I'm getting really frustrated with the "villagers are helpful/no they're actually out to kill you" trope that seems prevalent in the modules and adventure paths of late. While this isn't this modules especial fault, I would've liked to see a village genuinely try and aid the PCs...but later be infiltrated by the cult.
In spite of the few plot/tactical faults herein, the combination of challenging, varied encounters, and a refreshing setting lead me to give Cult of the Ebon Destroyers a 4/5.