There are expensive packages guaranteeing 'priority standing' but surely they won't sell enough of them to fill the golden circle, so I would imagine it's first come, first served. In 2009, you could queue in the morning for a wristband then come back. At other gigs, you queue all day to be at the front when doors open. Either way it's worth it to get down there by the stage when they come on. Will be a proper crush at the second barrier.