Maya 2012 Subscription Advantage Pack is basically Maya 2012 Service Pack 1 with with some additional functionality.
http://usa.autodesk.com/adsk/servlet/pc/item?siteID=123112&id=15500357
Maya 2012 Service Pack 1 is a free patch release located here:
http://usa.autodesk.com/getdoc/id=DL17847744
When you download both versions and extract them on Linux, the Maya 2012 Subscription Advantage Pack 1 has a lower cut version:
Maya 2012 Subscription Advantage Pack
Maya2012_0_64-2012.0-218.x86_64.rpm

Maya 2012 Service Pack 1
Maya2012_0_64-2012.0-386.x86_64.rpm

NOTE: I used WinRAR to extract the Linux (tgz) files on Windows.
In order to install Maya 2012 SAP, you can force the install (--force) or uinstall Maya and install the 'lower' but 'better' version.
Thanks to Nelson Cruz for sharing this interesting tip.
Epilogue
Maya 2012 SAP was finished before Maya SP1. Therefore, it has a lower cut number.