After some updates, I usually restart. As I am on an Arch based system, its usually at least once per week. Sometimes I am doing some projects, in which I want to leave the state as it is and not interrupt my "work". Usually this takes at least a few days, so during that period I don't update anything and continue my work. And sometimes at normal usage I don't need to restart, but after 5 to 7 days I "force" a restart just to get to a clean state again. Can't hurt.