Adding to it, I would suggest a way to keep track of down votes, at leastat least. A natural (and already requested) later improvement would be getting notified of modifications on posts you downvoted (though I'm afraid we're quite farwe're quite far from having it).
edit: Thanks to DMA57361's comment on another (already mentioned) questioncomment on another (already mentioned) question, here's how to see your downvotes: https://meta.stackoverflow.com/reputation and using audit helper script you can see it much better! So we're really missing just the notifications in this suggestion.