I've been using Atahualpa and very happy with it on several sites. My only issue has been the time that an upgrade of Atahualpa broke my WP-dTree menu system. When I inquired, helpful advice was given, involving bug fixes. At the time, I got my menus going by tinkering with some settings, but, since then, I have not updated Atahualpa for fear of breaking the menus again. I operate entirely through the WordPress system, doing updates from the dashboard.
My question is this: will an update of Athualpa result in need for bug fixes and tinkering with code? I can do a certain amount of that, but right now I can't afford to have the site down for the length of time it might take me to find info on this forum or such places. I understand that stuff happens. I'm not asking for absolutes, just for a reasonable assessment of the status of these changes. If there are measures to take before I attempt the upgrade, then I'd like to know what those are (bug-fixes?).