To be honest I'm not a fan of groups, so please forgive me!
Would love to have the function which allows me to search for groups (detail or model) that have only 1 instance, so I can ungroup and purge the group.
Work with large models and when our users use groups to lazily to families it make my blood boil!
Groups do have a purpose, I find most users miss use the groups and treat them like CAD groups.... I call it BAD Revit!
Sorry got the rant! 