I still didn't try to upgrade to de all new Sierra, to install El Capitan was traumatic enough. Today I did the latest update, not before a Carbon Copy backup. It was... usual: the system won't restart (are you sure wanna restart?), than black screen, white screen... I pick my guitar to keep my mind clean meanwhile the MacBook go crazy! But after half hour (even with SSD) it was completed, so it was usual! I lived the jump from Classic to the Unix version that Apple take almost a decade to accomplish (for real). I remember it was a shock! We lost speed and some "newer" aspects of Classic, we had to learn unix and type commands, etc., but Mac OS X really changed the world, all other system has basically tried to be like this. But we have reached two limits, thought: Mac OS X is not getting any better every new version as system, as before. I don't think they don't have qualified people inside Apple to improve it, maybe the model has reached the limit. Every project has a limit. it's a heavy 64 bit system single version with all you might want or like, with a lot of process that does not work in old or week machines and there is no flavors as Ubuntu, not even a 32 bit version as Windows. But unlike before, old machines are still very capable machines. Mac OS X is "free" because the cost is inside Mac price, a limitation in a world full of used Macs. The marketing plan has a limit either. I know a jump like this is painful, but my body is asking for it, soon! When do you think we will be shocked again by Apple?