I mostly use one, with occasional instances of two. For instance, I never downvoted the Popper troll from a few months ago, because every comment of eirs I saw was already at -20 and downvoting seemed pointless. My not upvoting Lukeprog is mostly two with a little bit of three. I used to use the anti-kibitzer, but it was preventing me from getting to know the other users, and long conversations with three people in them got confusing. I kept having to turn it on and off, and in the browser I had at the time that meant scrolling all the way to the top of the page and losing my place.