As for the "downvotes to show disagreement" problem, it's no where near as bad here as it is every single other place I've seen with downvotes. I do see one sided upvoting fairly frequently, but it usually is because the downvoted side is not arguing their position well, not because of their position. I'd say that the reverse is more of a problem, actually (poorly worded arguments that most HNers agree with being upvoted). Overall though, most downvotes I've seen have been due to poorly thought out or worded comments and comments that don't add value rather than disagreements. If you're downvoted here, you should generally put some thought into why. Every single time I've been downvoted, I've learned something from it.