I am not far off hitting EXP to go with BA Gold. AAdvantage is comfortable the best all round FFP in OW, with some excellent earning and burning opportunities. However, I am hanging on to BA Gold as I can make use of the BA Amex 241 voucher, and the one way award options have considerable value for me. Plus, BA are largely disinterested in anyone with status less than that so it is my lucky charm should I hit irregular ops.
As my other main OW airline is CX, I am happy to use EXP as they do care about other OW elites. Diamonds get superb service, but I've been well looked after with BA or AA in the booking.
QF's awful redemption rates should be enough to scare off anyone who has a choice.