Quora's a great site for those who lurk around, soaking knowledge from different topics from users all across the world.
However, its strict moderation, rigid rules and guidelines, and awful interface that causes lag is a turn off. And, there's a 1-in-a-million chance you'll get your answer answered, since it has to be well written, and follow the guidelines, otherwise, it'll be hidden from the rest of Quora until "proper" editing is made.
I like reading what writers write to difficult questions, and they're not as rude and immature as Y! As users, but there's something missing to Quora. It doesn't feel like you're actually connected to anyone (neither did Y! A have a connection, but...) Instead, everyone on Quora is like a robot, answering questions in lengthy detail.
Lastly, make sure you use your real name, or at least a full name that makes sense. I got temporarily banned because I used a nickname.