It only seems to work with comments made by a particular user.

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3 comments, sorted by Click to highlight new comments since: Today at 8:51 PM

You can sort posts by score by going to the all-posts page and sorting by "top".

(if you are thinking "huh, that's reasonable, but I notice the all-posts-page literally isn't linked from anywhere what up?" the answer is that "it was in beta, it'll replace the daily page someday soon, after we successfully make sure it's strictly better than the daily page, and will then be linked pretty prominently.")