The longer I play this game, I have the impression that none of the developers have even tried to play it before the premiere. Already bypassing the amount of serious bugs, the game has terrible design problems.
Yeah, I'd like to believe that they do play their game, but the problem really is their design philosophy. It's very inconsistent, for one. If this game is anything like Kingmaker, then the early levels will be brutally punishing, but then it starts to get easier and easier, as you catch up and eventually get ahead of the power curve. Until they decide to come up with 2 or 3 of the cheesiest enemies and copypasta them 50 times all over the dungeon. And sometimes you get the feeling their idea of fun is to try and make things as painful as possible for players. So if you're playing the game for the first time, not knowing what to expect and what you should prepare beforehand, you're in for a world of pain. I play many other games on high difficulty, and I think the design philosophy in these Pathfinder games is the most... problematic.
For me the difficulty curve isn't an issue. Rather, that feeling of low level fantasy adventure from PK, which reminded me of BG1, is gone. WotR starts out slowly, but then the mythic part arrives and it feels like playing BG2, except you go from Irenicus' dungeon straight to ToB. You get all those epic powers and enemies get high spell resistance, high ac, high saves and a list of immunities and resistances to balance it out. In BG2 you didn't get "improved alactrity" at level 6, but neither did you have to worry that much about highly magic resistant enemies early game. My party is level 6, in chapter 2, and only Ember can reliably use offensive spells, because as an elf she gets a bonus to spell penetration on top of the feats. Because the spell penetration feats alone are not enough. It wasn't like that in PK.