I agree that this is possibly the best general solution, and perhaps even the only solution, but it is certainly not "quick" when there are thousands of comment

I agree that this is possibly the best general solution, and perhaps even the only solution, but it is certainly not "quick" when there are thousands of comments and only one moderator. The only way to keep human moderation workable is to keep the work of each individual moderator small and scale out tree-style. Perhaps that will be the ultimate shape of the Web: a set of top level news sites, aggregating the best commentary from a larger set of second-tier news sites, aggregating the best commentary from a larger set of tertiary news sites...