<p>I think <a href="https://cooking.meta.stackexchange.com/questions/913/what-is-community-wiki">the community wiki FAQ on cooking.SE</a> answers this question excellently. Since both questions and answers can now be edited by anyone, regardless of rep (albeit with moderator approval for those of us with low rep), there is almost never a good reason to use community wiki. This even applies to most list questions. </p>

<p>Considering the ability for anyone to edit, <strong>the only value in community wiki is to deny reputation</strong>. This is potentially useful for avoiding rep farming, and filling the site with relatively useless fun list questions. Many questions of this type should just be closed anyway.</p>

<p>Community wiki is also potentially detrimental for the same reason: once there is no rep gain, there is less incentive for someone to spend their time writing a good, detailed answer.</p>

<p>Because community wiki can not be unapplied, it should be used judiciously. I would suggest that we adopt something like the cooking.SE guidelines linked above. Thoughts?</p>
