Ask HN: Pros and Cons of an invite-only launch?

Our team has decided to launch CentUp by scaling up to about 5000 users in a controlled manner. We've gone back and forth on whether we should open up to the public or stay on the same path. One one hand, we're dealing with a small team and a complex system that could fail. On the other, an invite system ads steps to a sign-up process that might turn potential customers away.

What have your experiences been?