get/set methods are typically invoked multiple times in the
JSF lifecycle, which is why they should not have side-effects.
6000 items in an update is WAY too much, however. I'm suprised you can turn a page around in less than 10 minutes. And I'd hate to be the person who had to read such a monster.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.