SharePoint 2016 was released in the Spring of 2016, and builds from many of the features already introduced in Office 365. Though SharePoint 2016 does have new features, most of the features are behind the scenes, from the administrative perspective. Much of the user experience, social, and content management experience is untouched (as is the ribbon), with some exceptions.
Among the new features:
My company, Prescient Digital Media, has been using SharePoint for 10 years; we've been working with SharePoint on behalf of our clients for even longer. SharePoint has been our primary intranet for 8 years, and has more pros than cons, but it's not an ideal fit for every organization.
Prescient principally uses Office 365 - SharePoint Online (almost complete feature parity with SharePoint 2016) for Enterprise Content Management; improving the way our organization functions in terms of employee collaboration and knowledge sharing specifically via document management, and social collaboration (discussion groups, profiles and blogging being the most used social tools).
The solution could use improvement, however, in terms of Web content management / social media tools (e.g. wikis), and general usability. We also encountered many, many problems with deployment -- customization and implementation requires more work than you expect. Additionally, like most organization, we customized the user experience, which can break (particularly specific webparts) with every SharePoint patch and upgrade. However, we found no issues with stability or scalability.
We switched to SharePoint Online because its the market leader, and 80% of our clients use SharePoint. We are first and foremost SharePoint intranet consultants, so we build and design other intranets, and need to deeply understand the ins and outs of SharePoint.
The initial setup was very complex and required a lot of work to customize, including hiring outside experts. The advice I would give to others looking into implementing this product is plan, plan, plan, and plan to run over-budget (unless you hire very strong outside experts to develop and run your plan and budget) for customization activities. And do not underestimate the infrastructure required (servers, and farm configuration).