I upvoted your comment, but presumably the idea is to get to HN-quality commentary mechanically (rather than having a handful of human moderators doing all of the moderation).

That said, I think the highest quality forum is currently lobste.rs. It might just be that smaller forums are easier to moderate, but also I think lobste.rs' moderation isn't vulnerable to some of the exploits that HN's moderation succumbs to. For instance, on HN if someone posts something mildly negative, they'll likely get moderated; however, if they post something that's pretty obviously hostile (to most people, anyway) but with the thinnest possible veneer of plausible deniability, they're not likely to be moderated (and anyone who challenges this plausible deniability may themselves be moderated for violating the 'assume positive intent' guideline). Lobste.rs' moderation lets users flag violating posts and too many flags will result in some moderation--I'm sure this could also be abused, but so far it seems to be doing a good job--maybe there's something Zsync could learn from their approach as well?