I am against banning Caledonian. He's impolite, but not a troll. He seems to have genuine disagreements (though it sometimes takes prodding for him to elaborate on what those are) and doesn't spam with lots of posts or even really long ones. It's actually the opposite. His comments are usually too brief, as if he thinks any moron should get the obvious point he's making. He doesn't disrupt the conversation and in numerous threads existing dialogues have proceeded as if he wasn't even there. There are plenty of comments that just consist of "Eliezer, you're awesome", as should be expected given Eliezer's awesomeness. I think its good to have people around who don't hesitate to point out even minor errors.