While DFW is a nicer terminal (at least when I used QF/AA) than LAX unfortunately due to cutbacks when we arrived there were only 4 desks processing immigration for aliens and it took just over two and a half hours resulting in a missed connection. Absolutely no exceptions made for faster processing of pax with connections. So personally I would choose on price and schedule, not to mention A380 over 747 rather than terminal. Unfortunately it seems international arrivals at any US airport are now a nightmare.