"Is meant to work", or, "ends up working in practice"?
Is meant to work. The whole point of consensus is that you should never have to determine what it is, because once you've reached consensus, people stop arguing. (We actually go for "rough consensus" on Wikipedia, which ends up being closer to "supermajority" than "consensus".)
The problem, of course, is that you can end up with decisions biased pretty heavily towards people with obsessive personalities and waaaaaaay too much time on their hands.
Yes, some people having louder voices than others can skew consensus, but you're more likely to end up with simply no consensus rather than the wrong consensus in such cases.