You can choose from several categories (at different prices). Economy, business and first; and within economy and business - better or worse seating area (in terms of viewing). Within each category no idea how they allocate other than obviously keeping couples/families together. I have a suspicion that Qantas did the allocating - cant think of any reason why I'd manage to get a bulkhead other than my QF status.

Most people, other than those in the window and one seat out, are up out of their seats. Not sure whether its worth paying the extra for a good seat as there is good cooperation so everyone can see.