The beginning of this post (the list of concrete, powerful, real/realistic, and avoidable cases of irrationality in action), is probably the best introduction to x-rationality I've read yet. I can easily imagine it hooking lots of potential readers that our previous attempts at introduction (our home page, the "welcome to LW" posts, etc) wouldn't.

In fact, I'd nominate some version of that text as our new home page text, perhaps just changing out the last couple sentences to something that encompasses more of LW in general (rather than cogsci specifically). I mean this as a serious actionable suggestion.

For the sake of constructive feedback though, I thought that much of the rest of the article was probably too intense (as measured in density of unfamiliar terms and detailed concepts) for newcomers. It sort of changes from "Introduction for rationality beginners" to "Brief but somewhat technical summary for experienced LWers". So it could be more effective if targeted more narrowly.