Export or list system settings that deviate from defaults
You might diff the output of defaults read | awk 'length&lt;200' on the current installation and a VM. Or convert the plist files to XML first with something like plutil -convert xml1 ~/Library/Preferences/*.plist.

It would be difficult to do right though:


There are probably thousands or tens of thousands of settings that have been changed.
Settings are stored in different directories like ~/Library/Preferences/ByHost and ~/Library/Containers/*/Data/Library/Preferences.
Many settings are for things like the positions of windows.
Some applications like Chrome don't even use the defaults system.
Many settings can't be modified with defaults or PlistBuddy.
There are a lot of changes between OS X versions.


It's easier to just copy the plist files or recreate settings from GUIs in my opinion.