Act 3 was the highlight of the game for me. The only thing that was really jarring was the emperor/orpheus debacle that made 0 sense.
Orpheus turning into a mind flayer (WHAT??) And the Emperor joining the Elder Brain (WHAT??) made absolutely zero sense whatsoever, neither in isolation or in respect to how I had played the interaction with the Emperor up until then. Couldn't just Orpheus be fucking ORPHEUS and go super-sayan on the mind flayer like the demigod-level psychic he's supposed to be?
Everything except the clusterfuck of an ending story-wise, I had a grand time in act 3. Though the bosses needs +100 HP.