I think MetaFilter works because of the relative low number of users, and their selection, since it's a paid website (to comment, at least).
I'm only a spectator there, but I've noticed the threads are much more personal. I think you can even see the individuals that favorited a given story or comment.
Don't forget moderators who are dedicated to "doing it right". You do kind of have to figure out and fit into the culture there.
If a new user doesn't get it and causes problems the mods will usually politely PM them and talk to them about what's going on. If the user continues to cause problems (start fights and just generally be inflammatory to the community) they will have no problem banning them.
They also temp-ban users who they know are normally well behaved when they are clearly having a bad day (which usually just means that a particular thread on a particular topic hits too close to home and they just can't be civil about it).
I'm only a spectator there, but I've noticed the threads are much more personal. I think you can even see the individuals that favorited a given story or comment.