Barely. The explanation of what you're opting into is terse and vague enough that most people won't really understand what's going on, and if you decide not to opt in, FB wipes out almost your entire profile.
Edit: I guess the point I'm trying to make is that Facebook actually tests the UI and copy in experiments and in the lab before deploying it; so when you make a claim that it's not working, I'd like to see some supporting evidence.
What isn't opinion is that opting out results in wiping out almost everything from your profile. That's a fairly punitive action to take against someone who doesn't want to opt in to an "opt-in" feature.
And saying that "Facebook actually tests the UI" means pretty much nothing to me. Do they publish the tests and the results? How confusing can a feature be before it's scrapped? Does the importance of the business function the feature supports affect that threshold? On top of that, given FB's history of privacy screwups and subsequent rollbacks, why should I have any faith in the company at all in this area? FB has always seemed more than comfortable with the "ask forgiveness rather than permission" model.