I think it will go all right on the Aust - LAX - Aust sector, because the type of cargo carried is no where near the weights to Asia. To Asia there is a lot of meat carried, where I've rarely seen this go to LAX.
On the 747-400 (non ER), it was only sometimes (not every leg) that cargo was offloaded. On the ER of course it is less of an occurrence as the -400.
Overall I think it will do as advertised on these runs, though haven't seen too much of it myself yet. On the first flight it was about 12-T off MTOW.