My institution is migrating from Claroline and we encounter some difficulties with groups auto-creation.
While defining groups, our professors are used to associate a sharing folder for each group and sometimes other tools.
In Claroline, when you auto-create 100 groups, you can have them associated tools activated for each group : sharing folder, forum, wiki and tchat.
It is possible in Moodle to restrict an activity or resource to a group, but when you have 100 groups the job becomes a bit boring.
It would be a good idea to have some checkboxes in the auto-creation groups screen for folder sharing and other tools that can be interesting to have restricted access for a group.