A lovely product for fey focused DMs who enjoy the slightly darker aspects of those mythological monsters (well dark as in the more fun kind of dark, thinkPans labryinth or a Neil Gaiman Story). Along the twisting way is full of stat blocks for end game bossese to early level fodder making sure that you can keep using this product for all play ranges. The artifacts and locales will want players to keep exploring the Demesnes of the fey soverigns (and Red Jack) even as they have to fight the inhabitiants as well as the enviroments as well. Each chapter has a short little tale to set the mood and even a few excerpts from classical literature to hint at their inspiration.
This product however is mostly supplementary though, while it is full of locations and lore it lacks a main focus on the material plane, which is a plus since it leaves the DM ample room to focus on that aspect of a setting, and with that being said i suppose one could run a campaign entirely within the lands of along the twisting way they'll just need to be very mobile or start off in one of the more friendly Soverign's lands.
My only complaint is that this book references other Fey Soverigns like Titania and Oberon without them getting stat blocks or Demenses. but the book is full enough as it is with fey and i'm certain that in the future Scott will take care of them (I also hope maybe he could add in the lady of the lake as well)
So in short pick up this product if your players love the feywyld and if you wish the Monster manual as well as Volo's Guide to Monsters had more of your favorite creature type, because i sure as hell know i do.
[5 of 5 Stars!]