Some feedback, errors and suggestions about Ubuntu MATE 18.04, using GNOME Boxes virtual machine:
The new "Customise Panels" feature on the Welcome Screen will be great for new users!
It's not fully functional yet, when I applied to change the panels, they disappeared and I had to reboot by opening a terminal with right-click on the desktop and typing 'reboot'. And after boot there was just an empty panel at the bottom so I right-clicked on it and redefined it... and the 2 panels were back and working. I think I was choosing the Familiar or the Contemporary layouts.
Suggestion about MATE Tweak panel tab: add a button to go back to the Default panel.
I can't scroll down the Control Center window, it stops scrolling in the middle/half
Caja's left panel icons/text could be resizable by right-clicking, like Dolphin(KDE's files manager)
Suggestion... Right-click on the desktop: a new menu item could be included like "Configure desktop", a direct link to MATE Tweak's Desktop tab, so people can easily customize the desktop.
We have green, orange, and that pale brown icons. I think there should be at least one blue icon theme on the list with blue folders... there's no blue iconset installed by default, suggestion: add Elementary icon set or another popular one like Papirus with blue folders.
I think there's room for improvement here, it's too simplistic and kinda ugly to be honest.