Since I’m also playing around with nvidia and wayland, let me add my experience.
I do NOT load sddm into wayland yet, I will try that soon too.
I wouldn’t say the user experience in wayland with nvidia is “horrible”. You will most likely experience glitches as flickering, strange positioning of windows and other small things like that.
Nightmode as mentioned above does not work (is addressed by kde team HERE and will be handled in upcoming updates)
For me, it also stopped me from using my favorite mediaplayer smplayer, but others like mpv and vlc still works fine.
I feel wayland is way more responsive though, like moving windows, moving cursor over applications menu etc feels “snappier” over all.
If I log out of the session, and then log in again, I SOMETIMES have to type my password twice, creating two instances, sometimes on the same tty (but suspended), sometimes on different ones etc, its just a mess. And if I then try to reboot/shutdown, the sessions don’t close down properly, changing to tty1 usually immediately finishes the shutdown/reboot process.
So I would say that as of this date, sure, install it in parallel and play around with it, but if you want a flawless experience, wait a few more months and stick to x11 for now.
Edit. Oh yeah, fogot the dealbreaker for me. Sometimes programs just stops responding properly (usually firefox but other apps have also been affected by this), creating a loop for the cpu for a while, then sometimes coming back (or I have to kill the process). That causes the icons on the KDE panel to freeze up, and if I close the program, I can’t open it from the panel any more.
I don’t have these, so I will try and see if that changes anything for me.