I haven’t experienced any deal-killing slow downs like some here, but I will say, as I’m mainly a dialogue VO editor, all of the extra, needless, accidental clicking I now have to do with the corner pop-ups, the ruler/loop and the cursor/timeline disconnection issue are by far the biggest annoyances and hurdles for me. None of these “features” are included in 7.5 which is where I lived until recently and still go back to occasionally. I am also still working in Yosemite as things seem stable. I’m too nervous about El-Cap on my now, older machine (2011) and I’m waiting until CB9 to pull the trigger and maybe with a whole computer upgrade next year.