Os únicos pacotes que estão no conjunto principal Mint (18.2 serena dist) são:
blueberry, caja-folder-color-switcher, cinnamon-core, cinnamon-desktop-environment, cinnamon-themes, folder-color-switcher, grub2-theme-mint, ia32-libs, iso-flag-png, libreoffice-style-mint, linux-kernel-generic, linuxmint-keyring, mate-desktop-environment, mate-desktop-environment-core, mint-artwork-cinnamon, mint-artwork-common, mint-artwork-gnome, mint-artwork-kde, mint-artwork-mate, mint-artwork-xfce, mint-backgrounds-maya, mint-backgrounds-nadia, mint-backgrounds-olivia, mint-backgrounds-petra, mint-backgrounds-qiana, mint-backgrounds-rafaela, mint-backgrounds-rebecca, mint-backgrounds-retro, mint-backgrounds-rosa, mint-backgrounds-sarah, mint-backgrounds-serena, mint-backgrounds-xfce, mint-common, mint-dev-tools, mint-info-cinnamon, mint-info-kde, mint-info-mate, mint-info-xfce, mint-mdm-themes, mint-mdm-themes-gdm, mint-mdm-themes-html, mint-meta-cinnamon, mint-meta-codecs, mint-meta-codecs-core, mint-meta-codecs-kde, mint-meta-core, mint-meta-kde, mint-meta-mate, mint-meta-xfce, mint-mirrors, mint-themes, mint-themes-gtk3, mint-translations, mint-upgrade-info, mint-user-guide-cinnamon, mint-user-guide-kde, mint-user-guide-mate, mint-user-guide-xfce, mint-x-icons, mint-y-icons, mint-y-theme, mintbackup, mintdesktop, mintdrivers, mintinstall, mintinstall-icons, mintlocale, mintmenu, mintnanny, mintstick, mintsystem, mintupdate, mintupload, mintwelcome, nemo-folder-color-switcher, nvidia-prime-applet, rhythmbox-plugin-tray-icon, syslinux-themes-linuxmint-cinnamon, syslinux-themes-linuxmint-kde, syslinux-themes-linuxmint-mate, syslinux-themes-linuxmint-xfce, ubiquity-slideshow-mint, ubiquity-slideshow-mint-kde, ubuntu-system-adjustments
Tudo o resto é direto do Ubuntu, do conjunto de espelhos do Ubuntu.
Basicamente, isso se resume a configuração padrão, trabalho artístico, etc.
Um desktop Mint 18.x parece melhor na primeira inicialização do que em um desktop Ubuntu 16.04, mesmo com o MATE instalado no sistema Ubuntu.