Out of curiosity, what OS did you switch to that doesn't require regular, and often large, updates? I can't think of an OS I've ever used – various Linux distros, Windows, OS X, various BSDs, Solaris, and a smattering of random other unix variants – that didn't require some form of regular update that often required (or at least strongly suggested) a reboot. (Or the near equivalent of punting active users and relaunching a bunch of userland processes.)

Oh man, I remember my Gentoo days, where upgrading a single package would sometimes require new base libraries which in turn required a large chunk of the system to be rebuilt… definitely don't miss that process.