Boxes has a fantastically simple ui but, as was the experience of the author of this article, it is really easy to run into something you can't configure with it so you have to switch to virt-manager.
FWIW, I got leary of Gnome Boxes (probably because I usually need to run a commercial OS like Windows) and found myself pretty happy with quickemu/quickgui - https://github.com/quickemu-project/quickgui
It works for what I need, but yes, if you need to configure something it doesn't support, it's a hassle. If you reconfigure it in virt-manager, Boxes will happily run the new config, until you change something else in Boxes, and then it will obliterate your changes.
The one problem I have, and I can't figure out if this is Boxes or something else: If the machine suspends, spinning it back up again results in a wrong clock. I can reset it, but it doesn't set itself automatically. I can't even find reasonable documentation on the issue.
Fedora has chronyd installed by default, which is supposed to do what ntpd does.
I also installed the guest agent. This is one of those have-to-use-virt-manager things. It doesn't seem to fix the time, but then I have been running it from Boxes. Maybe that's why.