Expire IIS response headers for an MVC app

Should we set the Expire Response header in the IIS for an MVC application?

If we do so, don't we risk showing stale content to the user?

Or is it that the browser automatically detects a change by doing an if-modified-since request for each file? Does this not defeat the purpose all together then?

Please suggest if I should set Expire Response header in the IIS or skip it? Is there any caveat involved in setting the expire response headers?

Thank you for reading. Any suggestion would be appreciated. Thank you again. :)