re: Tree-style comments are not the best format for every type of discussion.

But it sure fixed some of the more infuriating aspects of classic / linear forums:

- long (winded) conversations between posters in threads

- off-topic discussions / people de-railing the threads

- finding things from specific dates in very large threads.

Some of those things are easily fixed with very active moderation - but self-moderation (via voting) sure works fine in most cases.