From what I remember, it seems that downvoting a post impacts both the reputation of the poster and the down-voter. Honestly, i tend to lean towards just upvoting those posts I find helpful, so take that with a grain of salt- something has to be really egregious or flat-out wrong for me to down-vote.
In my experience, there seems to be a lot less flaming and trolling than there was here ten years ago. Mostly, posts are answered by knowledgeable folks that give smart answers. There are some users that are a little on the brusque side, when newbies ask really obvious questions, that are either going towards the wrong direction or could be easily resolved with the tiniest amount of google-fu, but I don't see that as a real problem, so long as people remain courteous.
Compare with StackOverFlow, where worthy questions get shot down and closed all the time.