The one big advantage for Qantas' FFP is that you get 100% of miles, on discount eceonomy tickets, when flying Qantas. I believe that this includes codeshares. QF Recently upped the numer of miles needed for flights but if you're flying discount eceonomy, 100% of miles is better than 25%.
Also, you can claim miles when flying transatlantic on both BA and AA. You won't be able to do this on BA with American flights.