Big no from me as well. As you have the "quote " facility and the ability to send private messages so you can actually reply to who you want to so whats the point of trying an two tiere system ? I've certainly seen alot of conversations dotted around other ones and it works ok. Lord knows I've written some tripe on here - most of us have, but I'd go to the "top tiere" still thinking I'm knowledgable enough, and unless it was password protected most people will stick their oar in anyway, in fact it may end up becoming a beacon to folk whose only mission is to make life difficult for those more highbrow (?).

As RWS has said, moderation has been swift, fair, and by the look of it mercifully rare.