As people have pointed out, a tension indicator would not have to be visible pre-vote, it could just as well be post-vote. I was split on this, either way would be satisfactory to me since I'd likely be voting on an interesting node to begin with.

The default in the user profile could be off, I agree. This makes sense in light of bombarding newcomers with strange data.

Another possibility: It occurred to me last night that the number of highly contentious nodes might not be very large. Perhaps a better solution would be a "Most Contentious Nodes of the day/week/month/year" along the lines of Best Nodes and Worst Nodes? I know I'd go visit the thing.

Matt