I like this idea. Four buttons: "good comment", "bad comment", "I agree" and "I disagree". Agreement vs disagreement would be displayed but would not determine

I like this idea. Four buttons: "good comment", "bad comment", "I agree" and "I disagree". Agreement vs disagreement would be displayed but would not determine comment position or commenter karma. Comment quality would determine comment position and give the commenter karma, but it would not be displayed. I don't know if it's right for HN, but I'd like to see a site which did implement this kind of two-dimensional voting. PS. Good comment, I agree!