I don't know.
From what tidbits I've seen, there's a fair mix of interest/uninterest for me. However, the key thing for me getting this book is if it's viable for me to use for my campaign, & it's Prime Material focus.
I never really was interested in Planescape or the like, because I didn't like the idea of advetures stomping around what effectively (for many of them) is equivalent to Heaven, Purgatory, & Hell. Don't really care for the idea of adventuring in the lands of the afterlife, so to say. For me, it sorta takes the "oooph" outta these planes & creatures from these planes.
Then again, I don't care for WW's WoD because PCs can be vampires, werewolves, & whatnot--sorta become the blah standard instead of the thrilling & scary unknown (which, IMHO, is what adds a lot of mystique & power to these creatures).
Still, there appears to be interesting tidbits in the book, but I don't know if the ratio of useful/unuseful material (for me) will be enough in favor for buying the book.