Icons in task manager plasmoid are way too big also, this may require a manual qml override in /usr/share/plasma/plasmoids/org.kde.plasma.taskmanager/contents/ui though as the Icon size System Settings don’t have an effect.
EDIT:
Temp fix was the make task list panel shorter, which automatically shrunk the icon size … pretty hacky though, be nice to be able to control it.
BlockquoteAre you sure about the hover…?
Yes that box is unchecked and if I move over the categories it jumps to that menu. It defeats the idea of having favorites to launch most used applications. At least in XFCE you can resize and use click only to keep the favorites open with out jumping to another category.
Have you tried changing themes? My Icons went super tiny. I tried all sorts of things but in the end I had to change my theme. I’m hoping my regular preferred theme gets updated soon. The qml file didn’t make much sense to me, my knowledge is a bit limited although I am perfectly happy writing on config files.
All the text within other plasmoids (ie netspeed, hw temps, weather, cpu util, etc) on the panel is significantly smaller, practically unreadable.
There seems to be a lot more padding around panel elements in 5.21, so I had to enbiggen the main panel height to make them readable again.
@otherbarry Yeah, exactly the same issue. Try running a different theme and see what happens…
I really don’t like Breeze, I use Oxygen with Breeze Dark colors … maybe that is the issue. Though Oxygen is officially maintained by KDE, so it should be okay, but is probably a regression.
TBH I couldn’t be bothered changing everything to Breeze just to have to change it back again.
I get ya! I used to use Oxygen but found some icons were missing. Then I found a mix of Gently/Oxygen/Breeze-Icons worked as my perfect setup. Unfortunately Gently is not playing nicely with 5.21 yet, so I’m on a kind of fallback at the moment just to get something usable. It’s only day one though. As things progress I’m sure it will smooth out. Remember the transition from KDE4 to Plasma? Ouch! 
Gently konsole theme is great.
Are you using the gently icons? I think that is what @wordler was referring to.
The panel was badly messed up for me though. I’ve had to change for now.
It is great, I use the drop-down terminal from Gnome/GTK though. The KDE drop-down didn’t do everything I wanted and the GTK on works just fine.
The Gently icons are fine, but they are basically the Breeze ones anyway, I can’t see any difference.
I am also enthusiastic and generally positive about the new plasma rework, though a bit disappointed about the fact, that none of the launchers are in any way resizeable. Up to this point, Tiled-menu worked well … but from now it is not resizeable anymore like the rest of the launchers. So I altered the kickoff menu …
I edited the /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentaion.qml
File
altering the lines:
Layout.minimumWidth: Math.round(PlasmaCore.Units.gridUnit * 20 * 5)
Layout.maximumWidth: Layout.minimumWidth
Layout.minimumHeight: PlasmaCore.Units.gridUnit * 50
Layout.maximumHeight: Layout.minimumHeight
( restart the computer for the settings to take effect )
so now I can live with, as soon as I fill up all and rearrange my favorite icons.
That looks nice. I still use the old Application Launcher menu with cascading pop-ups. I prefer that but it’s a shame they won’t let us resize the menus now. XFCE is more friendly with that, although limited in alternatives. Maybe I can find a way to hack that in a config, or someone else more skilled 
I use the panel view.
Keyboard is acting funky with the update. I can type just fine, but keys no longer repeat if held down. I think it’s kwin related, which replaced kwin-lowlatency since the AUR maintainer basically took it out of service with the newest plasma.
Feb 17 17:42:56 kwin_x11[2098]: kwin_xkbcommon: XKB: Couldn't process include statement for 'us(\0)'
Feb 17 17:42:56 kwin_x11[2098]: kwin_xkbcommon: XKB: Abandoning symbols file "(unnamed)"
Feb 17 17:42:56 kwin_x11[2098]: kwin_xkbcommon: XKB: Failed to compile xkb_symbols
Feb 17 17:42:56 kwin_x11[2098]: kwin_xkbcommon: XKB: Failed to compile keymap
That one used to get me confused on KDE4 because I had to many applications! 
D’oh! I scrolled through the thread too, missed that. Thanks!