My mileage varies somewhat.
I agree that for replies to anonymous coward it is very important to approve posts, else they don't see their own questions. But registered users with even a small amount of problem usually don't have trouble finding responses to their posts. I see nothing wrong in replying and voting on mildly obscure threads.
Also I would like to suggest that if you are thinking about reaping a node, please rethink that. Our problem is not so much ineffective reaping as too much reaping IMHO.