I think the big boards forum should be private as I don't think big-board admins will be happy to discuss issues where everyone can see. It's a known fact that one of the first places trolls look for info about 'admins' (of boards they have been banned from) is on the board software's forums.
I also think it would be cool for the coders to have a secret hang-out too - some where without the 'hussle & bussle' of the main site. I know it would be a good resource for non-coders like myself, but in this instance and as Marcho mentioned, I think the coders could do with such perks to help revitalise that feel good factor