The major difference, to me, between Slack and Office is that Slack lacks user lock-in. Companies that make heavy use of office would find it very difficult to

The major difference, to me, between Slack and Office is that Slack lacks user lock-in. Companies that make heavy use of office would find it very difficult to move over to another office suite (if they could find one that meets their needs), whereas moving off slack to one of the many alternatives, doesn't seem that hard.