In my group (Chess Empire) I have about 90% agreement, which seems a good result compared to other teams. TDT also has 100% often.
American group has around 75. It could be higher if I didn't throw out what move everyone to vote for at 10:00 PM with 16 hours left :D.
I can't stand vote chess for this very reason. The top 2 or 3 rated players in the group will go into the thread (even though they are the last players that need help finding a good move) and discuss everything. Move by move they present very strong lines. Often enough these players are willing to share home-cooked opening novelties that could/would score some very quick wins. But the lowly rated 12-1600 players (sorry to generalize) look at the position for two seconds, throw some vote out (sometimes hanging a piece they're so weak) and walk away. This isn't a huge problem, as the majority of drive by voters will vote different things, and the small group that is invlved in the discussion will still have the most votes, but in the opening, it's rediculous. The top few people agree that a particular group (after hours of studying the games of their top members/the games of the group) would have trouble facing a particular opening, (ie. the Sveshnikov). Then, a flood of patzers join, who either 'drive by' vote, or read the thread, respond "Stuff it, d6 voted" and ruin our shot at a sveshnikov.
If there are any vote chess groups out there that aren't useless, let me know :).
-matt
I am a member of Black or White, who for a time had the highest perfect record on chess.com (27-0-0 if I remember correctly). There are often 50 comments for each move, some posts as long as a page. And yet I have never seen anybody go to the trouble analyze an opponent team's vote games or their members' games, simply for the purpose of choosing one out of a number of oft-played opening lines would be best against a particular opponent. If you really do this in your group, I'd like to know its name