I manually curate 100% - I don't like the idea of not knowing what I'm voting on :)
I try to respond to all my replies to my blogs. Obviously, the nonsensical ones or those that have not read the post get ignored, but I upvote the posts because I feel it encourages the newbies to interact.
Today's experiment has shown that I need to research further. It may sound mercenary, but I'm no longer upvoting those that comment but didn't upvote - after the 30 minutes, of course.