General view from a few years on this board.
QF - Good for accruing status if flying in Premium cabins, However earn/ burn rates and taxes are bad. And has 4 QF segment requirement. Earns on Jetstar as well.
AA - Good earn/ burn but need more mileage to qualify in Premium. Status Challenge now has upfront fee and is AA only. Simple choice if you have US credit card for lifetime status.
CX - Tends to look after its own FF program very well (eg oneworld is Emerald is well down the order for opups)