Personally, I view the vote controls as a three-way toggle. Low-quality comments get down-voted, unless they're already greyed-out (no point in piling on, unles

Personally, I view the vote controls as a three-way toggle. Low-quality comments get down-voted, unless they're already greyed-out (no point in piling on, unless it's truly toxic). Comments that I disagree with but are otherwise well-written and contribute to the discussion I leave alone. And comments that I agree with and that are well-written I up-vote. But sometimes I up-vote comments that I mostly disagree with, but that I think make such an excellent point that others still might find them interesting. Or if a comment is greyed-out but I think it still contributes, I'll upvote it to counteract someone else's downvote, even if I don't necessarily agree with the comment. Ultimately, users can do whatever they want with the up and down arrows.