Interesting idea, but no. I like to read things in chronological order. Also note that some replies refer to earlier posts, even if they are not replies to that post.

I usually make a couple of passes on a node (and its replies), voting as I go, upvoting nodes that make good points and help illustrate the issue at hand, and downvoting (occasionally!) nodes that are counter-productive, insulting, flamebait.

I do tend to upvote earlier nodes, but that's just because I like to reward people who give the best answer the earliest. First Post nodes are rarely the 'best' answer, and hence rarely get my vote.

Hence, randomizing wouldn't really change *my* voting patterns .. since I'm assuming that's what you are trying to influence with your change.