Finally upgraded my 2011 MB Air (10.7.5), 4GB memory to Mavericks.\nUpgrade went very smoothly and took about 2 hours to download, install,\nand optimize. Only one app was incompatible so that's not bad.\n\nThe oddity is that when I press the Power button to shutdown, I have to\nhold it in for about 6 seconds before the dialog box appears. Under\n10.7.5, just touching the power button resulted in the dialog box\nappearing. Also, the response of the dock seems to be slow. Once the\ndock has been activated once, the response is fast. My imagination or\nwhat?