I like the idea of network, but also I have some negative feelings about HN/Redit.
The problem with the comments is that it is way to easy to go out of rails, then you need moderation and "karma" what I think is awful, because pushes everything to the uniformity of the "majority".
One idea (did not think it through, just a shoot in the blue): what if you can replay to other links, but you have to reply with a link? Yet one notch: you can replay positive or negative, that is a link in the same spirit/direction, or a link stating the opposite opinion.