One of the main things I use GAM for is to set the initial Group Permissions once the first GADS Group sync is completed. When GADS creates the Groups, it uses a set of default values that I want to change... such as Archiving the Group, Showing the Group in the Directory, Setting the Post permissions to Public or Domain Only, Specifying who can view the group content (Google Groups) to only the members, and a few others. My process typically starts with an export of all the groups, then use Excel (yes, still use it as opposed to Google spreadsheets) to build the four or five different GAM commands to set the various settings, save it as a batch file, and let'r run.
It would be nice to be able to configure one group the way I want it, and then use that group as a template to configure all or any other group.