Th issues Thomas presents involve the same old problems:tyranny of the majority and tyranny of the minority.
A majority on the DP could hide comments of an unpopular user.
This will back fire if the username of the hidden comment is visible. I can click on their username and look at a list of their recent comments and make up my own mind.
A coordinated effort by a minority could censor comments they want hidden for personal reasons. Perhaps a ratio of likes/dislikes combined with a minimum negative would work.
A coordinated attack (-7 in an hour) that hides "important" comments could be dumped in the moderators lap for a quick review. Certain users could even be immune to hiding by vote. Like maybe User #1 and friends.
Another way would be to delay it being hid giving more chance for a savior to come along.
I am taking for granted that all posts follow the swearing, smearing guidelines.
Maybe we should just play with it for a while and see what works.
Free includes debt-free!