Nice!
Thanks for reporting back.
Two of the bugs I reported are still open:
https://bugs.kde.org/show_bug.cgi?id=480721
https://bugs.kde.org/show_bug.cgi?id=477478
I have just updated my Plasma 6 setup again after having been offline for a time. I hope to do some more testing this weekend.
Dolphin doesn´t work at the moment:
Dolphin: undefined symbol: _Zls6QDebugRK11QDockWidget, version Qt_6
Anyone else seeing this?
Looking around on the big wide wonderful web I think this error may be caused by a partial update/upgrade. Will wait for a bit and update again, to see what happens.
Just updated, stuck in a boot loop now. 
System is broken at my end as well: the lock screen reports being broken and suggested doing
loginctl unlock-session 2
to get back into my session.
Partial update seems indicated.
Edit:
yup - konsole is not starting either.
Seems it’s a good day for me to not update lol.
Wise choice, sir. 
After opening your laptop’s lid, the brightness of its backlit keyboard is now correctly restored to the same value it had before the lid was closed (Werner Sembach, Plasma 5.27.11. Link)
I think some of us noticed something wrong with the backlight; not sure if they were on laptops.
I think by the end of february they will get a running and bootable plasma that will run very stable with very few bugs
They are indeed working hard towards that goal.
A grand endeavour.
Are your apps working again after the last QT update (yesterday?) I’m playing it safe…
Updated today using tty and it seems everything is back to normal.
Is adding applications to Favorites back?
Doesn’t seem to work here.
Confirmed - yay-ed, rebooted and things are working again here as well.
Not working here either.
It is working in QT 6.6. A patch for the QT 6.7 beta just dropped in the plasma-desktop package.
I decided to test Plasma 6, added the kde-unstable repository to my Arch and updated it. There were 2 GB of updates.
It didn’t replace many files, as several of them were migrated over the months to QT6 versions.
Upon restarting, one of the first problems was that the login theme no longer worked, so it switched to the basic sddm template. It leaves it in Wayland by default, but when trying to enter, the screen went black and my monitor kept blinking. I restarted again and entered in X11.
It was a mess, the scales of the apps and the taskbar were huge, I had to reconfigure everything, the behavior seems to have changed compared to Plasma 5, in theory, it was a little more correct.
By default the taskbar now floats. I thought it was ugly, so I disabled it.
The settings menu has changed, been reorganized, although it is still visually the same. But they moved several settings around, which can be confusing initially.
They added an overview similar to that of Gnome for using workspaces, it even works by tapping the mouse in the left corner of the monitor. I hate this behavior because my mouse pointer ends up there by accident.
The theme I used was Qogir and it was very disconfigured. I went to the settings menu and the add new themes button doesn’t work.
So I went back to the default Plasma theme. One of the most striking changes is that those blue borders that permeated all KDE apps have disappeared. Several lines also disappeared, everything became more simplified and without many borders.
Not all widgets were updated, such as the weather widget that I used, it has an error. But digging through the widget’s Github, the author made a new version, so I downloaded and installed it manually.
And from what I’ve read, this is a worrying point, as very few widgets have been updated for QT6. People talk about Gnome, but KDE also breaks extensions.
But while in Gnome, the Javascript code is easy to update (to the point that other people sometimes correct or fork), KDE Widgets are written in C++ and/or QML, which are a little more difficult to program. And now the widgets have to be designed to work in Wayland too, which adds a little more work.
While testing, I was finding that the behavior of the system in X11 was a bit bad, apparently it was left a bit aside. So I did some research on how to make Wayland work with Nvidia and discovered that I needed to configure some parameters in grub and mkinitcpio.
The Arch Wiki was a bit confusing about this, I ended up finding a more detailed explanation on the Manjaro forum (funny).
After restarting, the system logged into Wayland perfectly. So far, I think it’s excellent, better than in X11. Everything looks smoother, similar to what you get on Windows.
So far the changes are positive, they have corrected several small details in the interface, it looks cleaner now and the operation in Wayland is excellent, even with Nvidia. Apps seem to work fine, even the ones on Electron. We’ll see how it goes over the days, the change seems smooth, but I think that whoever customizes the system more will end up not enjoying it very much. The system’s standard customizations work, it’s more about customizations made by third parties.
I’ve just updated to this version of plasma-desktop. Indeed, manipulating the Favorites is now back.