I think on busy nights, such as a Friday night, when the drink is flowing, it is often fun to have all-talk on.
I know we've enabled it in the past, just by asking if anyone has any objections in chat. I guess the tags should probably show - that's the whole point of them. Some people would be annoyed to join a server and find alltalk on if it wasn't tagged. Even more so for ff and low grav.
Personally, I see no appeal in low grav. I think ff should be reserved for special nights when we've got a nice strong following, but definitely think there's validility in having a vote for alltalk (which I think is now very simple using SM).
It's hard though. Suppose a server of 24 people. All have joined knowing alltalk is off, and all are happy with this (hence they're playing on the server). If we raise a vote to enable all talk, then suppose 2/3rds of the 24 vote yes. Then alltalk is enabled - but we've just alienated a third of the server.
So we could set it so that we need 100% of votes for alltalk - but that would never pass.
I think it would be better, if, the vote was along the lines of "Would you prefer alltalk to remain off?" - then if say, more than 1/4 raise an objection, alltalk would stay off.
Now, consider the same process for ff and low grav. These are vastly more impacting than alltalk, and hence I think they should only be kept for advertised, special nights.