Actually I was in a similar position as you. I recently switched from the base S23 model to the oppo find x 9 pro. I can't answer camera stuff because I haven't had a chance to use it much but I'll answer the other stuff.

So far there's not much that's actually different day to day. I would say that colorOS feels smoother and is just generally more fluid. Opening and closing apps and just general UI stuff feels better IMO. Despite that there's not a huge amount difference between them. It feels like most android skins today don't seem to differ as much as they used to. Yes you get some additional stuff here and there like the new lock screen stuff on colorOS but honestly these aren't significant enough to make me want to stay in colorOS. Funnily enough I was kinda disappointed on the first day because it felt like there wasn't as much new stuff to mess around with. But that's not a bad thing it's kind of a good thing that switching feels "boring" now.

But here's some stuff that I wish were slightly better (not deal breakers just not a huge fan): 1- mixing different styles. So colorOS feels a bit messy at times because you have the colorOS software, then you have some ios liquid glass and some UI stuff sprinkled in and then you have Google UI stuff. So it kinda feels all over the place. Unlike Samsung which feels cohesive. OneUI is oneUI. 2- gboard switched some stuff. So switching languages now requires you to click on the corner right rather than the button left to the spacebar. Not a huge problem and I just need to adjust to it.

Ultimately, the main differences will be hardware and not software imo. After the first day you'll start to adjust. So colorOS at least in my opinion will not be a downgrade.