I see even more of an agree / disagree there than now, and I have the feeling that addicts to other forums will still see +1 / -1, although that might be just my number based brain talking.
But then I am not sure how much of an agree / disagree problem we have here anyways. I think current votes correlate reasonable well with informative and justified posts, of course with user ratings weighed by number of posts.
As an aside, I've been reading the threads in Ars Technica about their voting system. The user base there might have similar mentalities to here and the implementation is very similar, except that they have many, many, many more users and that they gave unlimited voting, both ways, to everyone, so most posts attract in the order of 100 votes (only in the first comment page, but that is another story). It is almost scary to read how those threads are a carbon copy of the ones here and how the point of view of the moderators is identical to the one here. Maybe there are some lessons to be learnt about what works and doesn't work there, as they are bigger and things evolve faster. In particular they don't think that they are creating an echo chamber. Some users are starting to think so, though, sounds familiar?
The only place where mods there see a problem with the voting is in threads about OS, like where androiders and applers gang on each other tribally. Interestingly, that is the very same problem we had here and it got more or less solved by removing voting from race and team thread.
Anyways, so far I have been reading the forum all too frequently to benefit much from the voting system, my vote often was first, but now I'll be off the site from Thursday til Monday, it will be interesting to see then how it looks after a race weekend when most people have cast votes before I read the posts; I'll have a more informed opinion after that.