Game runs much much better on base PS4 now. I would say it runs on par with The Witcher 3, performance wise, which is not bad at all. I have also noticed mprovements in certain areas that scratch that inch, like for example, ads and stickers around the world being clearly more perceptible & readable, especially at mid-high range. They no longer struggle to load, even pop out at a certain distance, and no longer have that ultra-low resolution than before. Navigation through UI seems smoother too.
Moreover, I do feel a noticeable improvement with the handling of certain vehicles.