At least every other day I see someone being downvoted into oblivion for espousing a contrary opinion, and while there is not enough upvotes to save that comment, I still kick one its way if the comment is thought out and posted in good faith.
My biggest concern is still about the overall amount of eyeballs moderating the new comments, and losing interesting or useful information. I almost think there should be a pending "downvote" to limit the number of times that people are reviewing a specific pending comment, so that if it is trash it dies and gets out of the way of newer pending comments worth reviewing, or maybe something where there are subgroups of pending comments so that you don't somehow languish in a low priority queue if no one looks at it, but instead get a chance at someone looking at it.
The 24 hour rule also is a bit sad because as far as I can tell, HN dies down a lot during the weekend, and some interesting articles come out that dont receive the attention they deserve. I imagine the same thing would happen with new comments.
I think that's not a bug, that's a feature. PG mentioned before that HN was growing too fast and that keeping up was hard. I'm guessing the problem trying to be solved is the Eternal September[1], and this feature does exactly that: you are only allowed to post once you learned how to behave the HN way.
[1] In case someone doesn't know: https://en.wikipedia.org/wiki/Eternal_September