Most folks using VSTS know that when you create a project in VSTS, there is a backlog created with a hierarchy of backlog items. The default ones I have are Epics and Features. The problem is while this may good good for smaller orgs, its does not work for the enterprise orgs I work with. With on-premesis TFS you can manipulate this in the xml and add your own items. Microsoft is introducing a easy way to do that in VSTS. I find most enterprises use one or both of these levels in the planning. The only thing is that its not out yet. According to Microsoft its coming in Q1 of 2017. So if you are looking to get the functionality keep an eye out in Q1 2017 for it to go live.