Vision can be complex and hard to pinpoint down. The believers know the power and what a great instrument it can be. The sceptics would say it is overrated and no a functional tool (often occurs in very sell-driven organisations.)
Down below is an excerpt from a Harvard study.
Unarguably brand visions are relevant for companies and ought to be a top priority for all organisations even the strong sell-focused organisations out there.
Remember it starts with the vision but it never ever ends.