I leave it totally open ended… Whether you’ve used them or know something cool about them… fire away!!!!(I though it would be interesting to start something like this, especially to help beginner learn and more advanced users to recap on some of the wonderful features of SharePoint that would otherwise not get the attention).
History; Document Sets are new since SharePoint 2010. They are basically a folder.. with metadata attached. And what is even cooler, the document inside those folders can have a different content type, while ALSO keeping the document set metadata!
Real Life: I implemented a solution once using Document Sets:
The client was managing Marketing Campaigns and every Campaign had metadata. For every Campaign, there were documents attached with other Metadata.
So, what I did was Make A Document Library with a “Campaign” Document Set Content Type which had all the Campaign Metadata. and inside the “folder’ they could easily put all the documents related to this campaign!
Furthermore, what is cool is Document Sets can have a Welcome Page (That Display all the Document Set Metadata when you are in it, so your “view” only displays document-pertinent columns).