I am a little surprised to see all the Act 3 performance complaints, though I have played on a somewhat below-the-specs PC (8 Gb VRAM, 32 Gb RAM, Ryzen 7), capping the framerate to 40 and turning the FSR on - still, the game ran smoothly and never once crashed.
Are people too proud to turn the settings down a notch?
Complaints isn't about performance, its unfinished content.
