For my work I have to deal alot with raw pictures and video files and since I updated my Macbook Air (2011, 4gbram) to Mavericks my workflow is intensely crippled. These are the main reasons: - this bug is makes me mad - handling raw pictures in Finder is extemely slow and makes my Air stutter (never had this stuttering before Mavericks, ever!) - preview of raw pictures in Finder takes much longer - 1080p videos from my camera are stuttering alot in Quicktime (maybe the worse problem of all) never had this before Mavericks Mavericks has some nice improvements like the better battery perfomance and some stuff but these problems make my Air feel like a much older Mac. My GFs Macbook Air (2012) still runs Mountain lion and before I updated to Mavericks my 2011 Air felt as fast as the 2012 Air. Now my Air feels like a much slower machine. Anyone feels the same way? What is the fastest way to downgrade to Mountain Lion?