Since the start of Stormblood, I put mine on the (upscaled) 4k pro setting for resolution over performance and hadn't changed it. The game played just fine, did not notice any slowdown or anything even in crowded areas.

Decided to try the performance (60 FPS) setting and it was a pretty big difference. Combat seemed faster and crisper especially the particle effects on spells and skills, very fluid. I do notice a small decrease in resolution, more so when moving it seems.

Not sure what I am going to stick with, on performance mode the FPS increase is definitely larger than the graphical decrease.

Curious what other uses settled on.