@Variante, since this has obviously been triggered by the +1 to your post being -1'd back to zero, two hours before the post in this thread. There is a big difference between a negative vote leaving the post with a net -1 and neutralizing a +1, at least there is in my head.
I checked your rep history, and you have two posts in -1. To both, I agree, very questionably so, but it wasn't those that brought you to this thread. The post in the Mercedes thread that initially got a +1 is, in my opinion, partially correct and partially wrong, partially informative and partially misleading, partially informative, yet so oversimplified as to not be informative anymore. In my opinion, I can't speak for everybody else and do not claim to be in possession of the truth. So someone thought it worth of an upvote and someone thought it wrong enough that a positive rep wasn't justified after all. This, to me, smells of peer review, and to me suggests that the system is working.
Also, when a post of yours in the Red Bull thread got first -1 and then got upvoted to zero, did you complain then?
I am guilty myself of being a serial re-zeroer. If I see a +1 or a -1 based exclusively on opinion, with no info content, I click it back to zero. Note that I can only do this once, if it is against the general agreement, it will be outweighed by the community. If I see a +1 given exclusively in terms of it being a funny post, I click it back to zero. Both are my little contribution to the T in F1T. And clearly, I am not the only one doing this, as your example proves.
Until recently, few people were voting, now I find that if I spend 1 day away from the forum, when I come back I find some posts rated, and those ratings are mostly a decent quality guide. Many good ones remain at zero, sure, but almost all posts with multiple digit reps deserved them, be it positive or negative, and anything with say, a +3, is deserving of a slower read, as it rarely disappoints.
In any case, whatever the voting system is going to do, it is finally starting to do it. Some 600 members can upvote and some 50 can downvote, so that votes are starting to be the norm rather than the exception. Looking forward to a live experiment on community self-control and keenness on keeping the house clean. And yes, there will always be noise in the system.
Edit: The "opinion" bit was added after some other posts were made, the initial tone came out a bit harsh, my apologies.