I hear a lot about those distros around here. I recently settled on openSUSE Tumbleweed after having used Fedora and ZorinOS for a while. It's so good, I haven't thought about switching to anything else. Manjaro, Pop_os, and NixOS are on my list if that ever changes.
I like AppImage a lot and I wonder why that didn't take off like Flatpak did. A timing issue, perhaps?