I normaly try to vote on replies to me on the same basis as other nodes, but I don't pay all that much attention to my voting habits, on the theory that they'll average out on the long term. OTOH, I very rarely downvote nodes, period. I almost always upvote a node that replies with a viewpoint or information that I hadn't considered -- including on replies that bombast me for not thinking of that viewpoint.

Really, it's not all that important how you vote, so long as you have good reasons at the time, for voting that way on that purticular node. (I'll sometimes "personality vote" for, or even against, a purticular person. But when I do, I look through their history, looking for nodes that are worthy of the vote I give them.)

As Jess, sitting next to me, just said "the general practice is, do what you think is right". I couldn't have said it better myself.