Since updating from Mavericks, My MBP- Mid2010 is unusable. Cursor is so slow and laggy it makes even the most calm people go postal. World of Warcraft? Ha, not anymore. Nice tidy 2fps. Manages to do Safari alright, but god help me if I want to switch to Finder to CONSIDER opening another application. I have reinstalled from fresh, twice. Doesn't help. Cursor is fine for approx 2 days. Don;t know if this is relevant, but my computer fan hasn't come on in forever. Does anyone know why the hell this is happening.