I've never actually used it. Every time I've followed a link there, I get a popup telling me I have to register before seeing any content, which I've refused to do.
That's been my experience. The few times I've seen a link because someone actually set it up correctly I was disappointed when I got to the actual content.
I wonder why they keep insisting on this obstacle. It possibly serves well as an audience selector. People who are too impatient to sign up should possibly be excluded from the user base that the founders of Quora have in mind.