yeah each airline has pros and cons.
I used to fly virgin, but were never on time, 2 years straight of flyign every 2 weeks to syd and never arrive on time.
when I changed roles to a customer facing one and had to be on time moved to qantas they more keen to put the pedal down if running late.
most of my friends who are serious flyers paying for it themselves are on virgin however, (easier to get status if nothing else)
but if you flying Intl often,and can get status..qantas is def your friend.