I am still happy with Xububtu 20.04, but I decided to have a look at Mint 20. I burned Linux Mint 20 Xfce to a USB flash drive using Startup Disk Creator. I was not keen on the default appearance of MInt, and decided to experiment with the Appearance settings.
The Mint-Y-Aqua Style with Mint-X-Aqua icons looked best. The panel (AKA taskbar) was huge on my 1440 x 900 monitor, so I reduced its width with the slider in Panel Preferences. I still was not happy with the icons, and decided to install the popular Papiris icon set:https://www.gnome-look.org/p/1166289/https://www.omgubuntu.co.uk/2016/07/how ... eme-ubuntu
I found the icon set by searching for “papirus” in the Synaptic package manager:https://geek-university.com/linux/synaptic/
The Papirus icons looked good, but did not blend well with any of the preinstalled desktop styles. I decided to install the more neutral Greybird Theme (which has been the default on Xubuntu for many years).https://www.xfce-look.org/p/1016618/
I found the Greybird theme on Mint 20 by searching for “greybird” in Synaptic.
The the edushechkina_ladybird.jpg wallpaper looked the best of the Mint 20 wallpapers to me, and I have copied it over to my Xubuntu system. (I also like jankaluza_blossoms.jpg from Mint 19.2, and have copied that over too.) I installed the Papirus icon set on the Xubuntu system. ePapirus (the version for Elementary OS) gave the best contrast for the for some of the icons on the panel with Xubuntu 20.04.
On Xubuntu 20.04, increasing the panel width from the default 26 pixels to 28 pixels changed the colour of the Papirus “show desktop” icon from grey to light blue, and made some of the icons (including the Xfce mouse "start button") much clearer. The power saving icon then looked rather big though. I did not need that (it's in the menu anyway), so I removed it.
Linux Mint has its own Software Manager for installing applications. I found this tutorial on installing applications on Mint:https://community.linuxmint.com/tutorial/view/1525
The recommendation is to run:
sudo apt-get update
in a terminal before installing an application with the Software Manager. I would have thought that would have been done automatically.