but on k5 itself and not here, where I should've, so it got smacked down quite quickly.
However, I don't think that there is any reason to timestamp the ratings. It serves no real purpose beyond weeding out who the kneejerks are, and even then, some people can read very quickly. Furthermore, it dosn't weed out the kneejerks who happen to read the thread long after you've made your remarks.
"Comments you've rated" would be an interesting feature on a mature, closed site. But in a public forum, all you are providing is ammunition for flame wars.
What I would rather see is a simpler +1/-1 system similar to the submission que. Either that, or some sort of weighted average mechanism that considers the number of users that voted on a comment in relation to the score. This is to prevent new comments, or comments that don't generate very many ratings, to be popped to the front of the que in front of comments rated by many. This would make comments earn their way to the top.
For instance:
right now, if a fresh comment is posted to the thread, all it takes is a single vote of +5 to send it straight to the top of the stack. So you set up 2 accounts and open them both in seperate browsers. One for the comment, one for the vote. Post with one. Refresh the other mod yourself up to 5. Now everyone gets to see your comments. Heck, create multiple accounts and then mod yourself a few time with 5s. Now you'll almost never drop below a high 3 or 4 unless you're deliberately trolling for 0s.