TBH, I can only say it's far more stable than openSUSE, Ubuntu and Manjaro which are the non-atomic distros I've used for a long time.
Aurora has never broken and I've never had any major problems that I can recall in over two years. I never initiate updates of the system, my Flatpaks or Homebrew. That happens in the background and whenever i restart (without me noticing).
It's Linux for those who have work to do and don't want to be a sysadmin for their desktop.