I am on one of the SFO-SYD flights, the later one, in December and both of the flights look sparsely filled. Already have the upgrade for the return flight.

I use to catch the LAX-SYD flight but it has a fuller load.

I personally like the later arriving flight (easier to adjust to the jetlag) and prefer the later flight when I return to avoid the commuters on the morning trains as i make my way to the airport so if they get rid of a flight hope it is the earlier flights on the SFO-SYD-SFO routes