I'm using a 3080 under Plasma, and I thought 555 was doing great, since I could finally use electron apps without input lag or flickers. I didn't bother much with gaming since VRR does't work if the NVIDIA GPU has more than one display enabled on it (you can use a second GPU or an iGPU to workaround that). I decided to give it a go anyways, wrote a script that turns off my second screen when I open a game and enables it again when it closes.

Unfortunately, 555 was unusable for me. After a short while, Xwayland would crash and either Steam and the game would instantly close or my entire system would freeze, requiring a reboot. I thought this was an issue with Steam, so after some extensive log collection, I opened an issue on their GitHub and shortly after a dev analysed them and told me that my issue was likely due to explicit sync, and asked me to downgrade to a pre-explicit sync driver.

I went back to 550.90 and my crashes stopped completely. It also stopped a coredump spam of glsdisplay by Steam, and also fixed a power draw bug in which my GPU would never go below 100W, even on idle. I never had issues with games flickering previously, and I still don't have it now, and I was able to fix the electron apps flicker and input lag by setting ELECTRON_OZONE_PLATFORM_HINT=wayland on my env, so for now I'm sticking to 550.

I also opened a bug report on NVIDIA's forums and I'm waiting for any input.