Why a wiki?
A wiki is digested ideas not a running gunfight.
A wiki has topics and links between topics. One advantage a wiki has over a paper Record is that it is a form of sharing information that allows for multiple crossreferences. Since a wiki is not paper, the extra crossreferences don't actually cost very much, and are essentially free after you pay the costs of making the wiki available on a computer.
A wiki Records consensus. It provides a place to build up the ideas from many discussions into a coherent point of view that reflects the output from the discussion. If there are alternative views they should be documented separately as a coherent set of ideas.
Dissenting ideas should be Recorded and eventually eliminated as their support wanes or should be incorporated into the final result as possible alternative approaches that could be adopted if we ever get to a set of actionable tasks.