Fedora installations have been pretty smooth.
ended up using the terminal for installing all updates.
My experience as well with my Arch installations after a decade with that distro. I run a system upgrade because I want to, not because I need to. Never does it break unless I'm careless when upgrading and not checking the news page beforehand, which you are supposed to do. As long as I play by the rules, it's super stable. (Never did it break for me anyway though. Never happened apart from hardware failure.)
Although admittedly I almost never do check the news page before upgrading, but/because there's rarely anything there. And after a while you learn to recognize the volatile packages which can break your system, so e.g. if systemd has an update I'll check the page before hitting enter, and so on.