Sorry, I know the difference between restarting a service and a kernel. But, as I said before and I will say it again, we are talking about a desktop here, clueless one, and the Xorg is only one in a long list of things that can broke in funny ways on upgrade. Can you explain to me why the average user (not the super geniuses like you :-)) would switch from windows to linux due to one functionality (upgrade without having to reboot, which once again I say that is debatable) that he does not need because he is using a desktop and not a server? And even considering also that in exchange for this functionality he would have a desktop that is, at best, problematic?
Clueless one, you are showing here, for all, another reason for the lack of progress in desktop Linux: You see it as a server. And the Average Joe do not need a server.