I recently strong-downvoted a post that I would have weak-upvoted if it had been at a lower karma. In general, I usually vote primarily based on what I think the total karma should be. I'm curious whether other people do similar things.
This is both a question and a poll. The poll is in the comments; it works via upvotes but there is a karma balance comment. (Note that one can recover the non-weighted results (i.e., number of votes) by hovering one's mouse over the current score.) This is about votes on LessWrong only.
I'm also wondering whether this behavior is, in some sense, anti-virtuous. If everyone votes based on what they think the total karma should be, then a post's karma reflects [a weighted average of opinions on what the post's total karma should be] rather than [a weighted average of opinions on the post]. This feels worse, though I'm not entirely sure that it is.
Correction: as jimmy points out, voting independently of current karma does not give you a weighted average of opinions on the post because there are only a limited number of ways you can vote.
Meta: There's been some speculation about this (maybe read after voting), but nothing conclusive.
Current non-weighted results (08/28 07:05 EDT) (TK is 'target karma'.)

Ok, I think I actually agree with your crux.
The points I was trying to make were (kinda scattered across the comments here!):
1. It is advantageous if people have a shared understanding of the system
2. Voting your own belief actually should work pretty well
3. There is a written norm in favour of voting your own belief
I think we disagree on all 3 to some extent, at least in how important they are. I think if we lose the disagreement on number 3 then disagreements on 1&2 are less important.
I'm ok with a norm of voting based somewhat on target karma (making it overly strong an effect I think would be detrimental), especially as this is now common knowledge and seems to be most people's preference.
This whole thing has resolved some of my confusion as to why karma scores end up the way they do.