Great question. I know that I choose not to upvote my own posts, because to me, it's almost like Liking your own Video on YouTube - Sure, I don't get the curation rewards for it, but I just think you shouldn't upvote your own stuff. Any time I've had the box checked at first, I uncheck it (or remove my vote which resets the curation rewards). I would feel 'less authentic and genuine' if I upvoted my own stuff - you know?
However, it's still perfectly fine to upvote your own posts - It comes down to what you choose.