Got the PS5 version of the base game a couple hours ago by setting up an AUS PSN account. Few impressions based on Quality Mode in chapters 1, 2, 3, 6, and 13:
- in general the textures are a lot better, practically all of the egregious ones like the aircon units, The Door, the scrapheaps and the slums in Chapter 6 are fixed. There's still a few grotty textures here and there but they're less easy to spot. Sector 5 and Wall Market are noticeably improved in particular.
- On top of the stuff like new lighting and volumetric fog, there's also additional particle effects, improved HDR (including actual calibration in the menu) and fairly limited ray tracing on select surfaces. I'd say of all the additions, the lighting and HDR are the star players - the overall image the game puts out is brighter and more vivid now, with the PS4 image seeming more washed out by comparison.
- I've so far not noticed any music different to the degree of the opening, which does appear to be a completely new recording. To what end, I have absolutely no idea.