I am in the process of seeing if I can update to Mavericks and am quite unhappy. In late December 2009 I bought my NEW iMac at the Apple Store with the Leopard os. I later updated to Snow Leopard. I have just now discovered that I was sold an "early 2008" model, 20". I had never measured the screen, but was told it was 21.5. According to their own build list, I see that there were 3 more versions of this computer introduced before the date of my purchase. There have been a couple of other issues that should've given me a heads up. I would like to know what anyone here thinks about this? I had never been inside an Apple Store, nor had ever used a Mac….what did they do? Clean out the back room when they saw an "idiot" walk in?