This book does a good job of meeting the players desire to play with undead and a Storyteller having to actually put it on the table. For example, other than the Skeleton, undeath is a class archetype. Want to be a lich, level 12, talk to your DM. Obviously some of these things can't just be picked without context or reasons but this gives access to a brand new type of character creation, playing dead PCs. I can realistically see more than one PC at previous tables taking on the mantel of a ghost archetype and having their driving goal bring them back from the beyond.
The undead companions are just so-so, honestly I'd preferred that one of the choices I get when upgrading my companion was undeath traits, rather than 'undead horse' but I can see why this was done as undead horses need an archetype specific master. I would however, had like to have the option of wolf+skeleton or wolf+zombie combination that would have let my existing beastmaster PCs bring their companions back with them, with the same-ish stat line. A Zombie Wolf with a 20 speed is a right terrible flanking buddy.
I really have enjoyed this book for hours so, that's worth my 15$ even if vampires die in the sun. However, I actually really like how all these rules work which I can say is rare with new mechanics.