I was thinking of adding a system similar to the one Paradox Plaza has, where instead of upvote/downvote, you can chose among three options: agree, respectfully disagree, helpful.
This has several advantages:
i. respectfully disagree is a much less confrontational than a downvote/dislike. Paradox Plaza is actually one of the most civil places on the internet.
ii. It saves you the trouble (and the risk of confrontation) to make a comment just to express disagreement with another comment or rectify a false piece of information.
iii. A reader can at a glance see which comments the community regards as more informative and helpful.