Well this week I did a round trip to Sydney on the 333. On the way down J was full, F had a couple of seats and Y was 80-85% (with lots of screaming kids - so no sleep
)
On the way back yesterday, F was full, J was over-booked, and they were offering AUD1000 cash to people to take a downgrade. Y was about 75%.
That doesn't look too bad - from a profit point of view its the seats up the front that contribute disproportionately.