I definitely agree the CB is not a viable alternative to an OT section.
And I don't see how it is useful for anything, except perhaps socializing for monks who wish to discuss about the weather or other such subject. I have sometimes answered on the CB (really rarely), but, frankly, I don't see the point of something so limited in terms the length of the message you can post, the time it will be shown and even the clarity of who is answering to whom. In brief, except for a very few exceptions, I am using the CB only for sending a private message to a particular monk, almost never to address the whole community.
But maybe I am just too old or old-fashioned for some modern technologies.