I really felt that OS X become less stable compare to Mavericks and Mountain lion. Let me ask this question: Why Apple updating OS X annually? It's too fast to update OS X every year that they don't fix bugs and issues within a year. My Mac crashed randomly and is unstable after Yosemite and El Capitan. If they can't fix these problems within a year, why don't they update OS every 2~3 yrs? This is a serious problem. I have Adobe programs that I'm using for my major and I really hate to update OS X annually but I have to since Adobe support new features in newer version. Apple forcing users and other developer a lot to update new version and this will make them tire and angry. Apps compatibility, developing apps for newer version, and etc. If Apple can't afford to build OS X perfectly, then they must stop this madness. OS X is seriously unstable than before. Im really seek of this terrible issue on OS X.