We also drove up our new F30 328i to Sydney to finish up the break in period, and then onwards to Port Macquarie over the Christmas break. Suspension was a bit rough over the older bits of road - so yeah, revalidating what J1n said, consider adaptive suspension if you plan on long/interstate drives.
Engine was under 2k rpm when cruising at 110, which meant plenty more power at hand for overtaking.
We were on eco most of the time. We probably could've made Melbourne to Sydney in one tank (didn't actually try this out, we refuelled just before metropolitan Sydney).
The drive back was about 13 hours, 1200km and averaged 6.1/100km.
