Virt manager is the least intuitive (discounting actively antiuser crap) program I've ever dealt with. I still don't quite get it and I've used Linux exclusively for more than 5 years.
GUI might not be as powerful, but in my experience, it's similarly non-intuitive as alternatives, such as VirtualBox / UTM (macOS) / VMware Fusion/Player.
For anything more complex (e.g. GPU passthrough) you will need to drop into manually modifying XML files.
The GUI. Random permission errors, python tracebacks, saving the settings don't always work, and the mysterious charade with "storage pools" that causes new permission problems.
I just started using Incus now. It seems way more intuitive. Its remote feature is amazing too.
