Not really. I seldom get an upvote, so my participation is not dependent on that, and I don't keep score. Also the ability to upvote but not downvote is lopsided as hell, and tends to sour the whole idea. I'll still upvote sometimes, if I really really agree or like the post, but not dependably. Lastly I don't really give a crap what my 'score' is, anymore than I gave a shit about 'gold' on reddit.