Akashic Mysteries has grown to become my favorite Dreamscarred supplement. I never quite dug Bloodforge or most of the Psionic books, and I absolutely love Path of War. But Akashic Mysteries hits a very good balance that I feel the other books, save maybe the Psionics books, don't hit. However much I love Path of War, I feel that it sort of leaves GMs out in the cold. GMs using Akashic Mysteries are much better-equipped: the races and monsters feel like a natural addition to almost any setting, the monsters are very cool additions or extensions of existing monsters (such as a Rakshasa that uses Veils).
The flavor of the book is decidedly different than most mainline Pathfinder, and that does a lot to endear me. It draws from Egyptian, Middle-Eastern, and Indian styles, which I feel is definitely a niche not tapped into enough. However, it doesn't feel alien to your 'normal' fantasy, like bringing in a samurai would be (not that I'm knocking it!), the Akashic material can fit right in.
There are downsides. The Daevic's Passions are hyperfocused on a handful of fighting styles. The archetypes of the book definitely show its age; a fighter archetype that gives up Weapon and Armor Training, an archetype for the non-Unchained summoner to me are Exhibit A of that. But a few duds in any Pathfinder book is nothing to cause an uproar about, I am just disappointed because I want to like everything in this book.
Overall, it feels different enough from baseline Pathfinder for me to like it. Psionics just felt like a different way to mostly do the same things, Path of War, while I firmly believe it's awesome, feels like a different approach to martials, while Akashic Mysteries genuinely feels like something that has not been tapped.
