The other downside of Features in Drupal is that if we export something as a Feature (say a View) and then our site builders tweak and change that View for our clients and then we update some core element of that View and re-export the Feature, that re-export will overwrite any custom changes that were made to that View, thereby trashing any of the custom changes. This is a real problem with Features to which I'm surprised there has not yet been a good solution.