I'm a big Nova Prime user, but I've been using my S22U on OneUI so far. I'm happier with it than I expected, after diving into Good Lock and related apps. The default grids are too large for my liking so it was a must.
The things I don't love...
1. Notifications are numbers or a dot, vs. Nova showing me visual representation (like the contact's icon/photo).
2. No gestures on home icons or docked icons, like how swiping up texted one person or down texted another, or launching visual voicemail swiping on the phone, etc. I used that constantly.
3. No scroll on the dock, I liked hiding the apps people don't need to see. LOL... like my secure folder, so it's very handy but not in plain sight.
4. I somewhat miss gestures on the home screen as well, but the swipe left for Google replaces one of my main uses so this is liveable.
5. App drawer! Although I found how to change it to vertically scroll, then I had to back out of it which was clunky/annoying. I also miss the tabs in the app drawer but am trying to just use folders again to help dodge both of these.
6. Icon packs. I found the ones in the Play store are better than Galaxy themes, but I can't apply them without a launcher. I miss my Flat Circle pack. Way more consistent and I prefer the shape. Plus I could hide text on the home screens, it's so clean.
7. Another small thing, but overlapping widgets and the ability to resize to your hearts content is handy when something has wasted space and I wish OneUI supported it (like making my weather purely show the temp and weather icon, I can't get it to do that now).
All of that said, I'm not bailing yet but do expect I'll end up back on Nova Prime.