I have Book of the Dead and it's okay but I kind of got it for the rules completionist in me? I think it's largely okay when it comes to the revision, though there are still a few things that reference using "necromancy spells", which is obviously not going to fly in a school-less world. It's got some neat things in it (undead eidolons and companions, some interesting archetypes whose specific usefulness I never really judged), but it's obviously got a lot of magic-themed stuff that might make things difficult. I will say that it does have a good amount of creatures to use for campaigns, as well as design stuff for undead stuff you can use on the fly. It's not a bad buy, but it obviously has a very specific theme.
I will say I like The Dark Archive a bit more. Being able to turn monsters into "cryptids" which are vulnerable to Knowledge Checks and other weirdness is stuff I can use more. The Thaumaturge and Psychic are both very cool, if a bit more complicated, when it comes to classes. Really, in general The Dark Archive feels a bit of a better buy, though I would be wary of what might change with the Psychic given that it's a spellcasting class, as well as stuff like the new Witch patrons they have in the book. But I find the book to be easier to integrate into a campaign compared to BotD.
Howl of the Wild and Rage of the Elements were basically made with the revision in mind ,but I know that a few spells/powers in Rage of the Elements have some desperately needed errata for a few powers which were basically missing crucial things like an area effect spell that was missing the whole "area of effect" part. I think the errata has been delivered in the last month or two, though, so it should be good.