If I download 10.9 today, is the installer a full 10.9.5 installer? If I had downloaded it in mid-June, would it have been a full 10.9.3 installer? Or are both of them the same 10.9.0 installer and upon booting, the OS will update itself to whatever is current? I ask because I'd like to know if the 10.9 installer I download today is a full 10.9.5 installer and will boot a mid-2014 MBPr which needs at least 10.9.4. If what is downloaded is only 10.9.0 and it needs to boot up to update to 10.9.5, then it won't work because 10.9 will not boot these Macs. So, when Apple updates OS X, do they build a new full installer that gets set to be the download package in the App Store so that the App Store is always a full installer for the latest OS version?