As others have said, check the deckplans - eg the ones provided by cruisecritic
Looks like you've been upgraded from CA class to BC class
CA is deck 5 midships balcony, partially obstructed (lifeboat directly underneath you)
BC is deck 8 midships balcony. Otherwise identical
The ship's motions may be more noticeable (the more you pay the more you sway) but unless you're very susceptible to motion sickness I wouldn't be too worried. If you're leaving on QE in 38 days that means you're going from Sydney to FNQ and back.
The seas should be fairly calm (especially on the inside of the Great Barrier Reef) unless there's another Tropical Cyclone offshore somewhere.
On deck 8 I'd mostly be concerned about being underneath one of the pools, but being midships you only have the Lido buffet above you.
Also you're now on the port (left) side of the ship, not starboard. So you'll get better views of the Australian coast (when nearby) but not the GBR.
If you're staying on for the NZ leg then you're more likely to get some heavy seas.