Recently I needed to update a Windows Azure Pack installation from RTM to Update 2. Because the servers had no Internet access, I needed an offline approach.
One way is to download the Windows Azure Pack 2013 Update 2 components, extract the files and install them one by one, thereby carefully checking that only the installed components are updated. It is very easy to make a mistake and add unwanted ones on a WAP portal server.
Because this approach only works for the WAP 2013 Update 2 components and doesn’t give you the partner components such as Gridpro and Cloud Cruiser, the offline Web Platform Installer approach is the best choice. In fact WebPI has been upgraded from version 4.6 to 5.0 containing Update 2 plus the 3rd party components.