I suspect that P&O Australia suffers from brand inconsistency with the other Carnival brands. Carnival are cheep and cheerful fun ships and Princess is an affordable premium product with Cunard a cut above that but where does P&O Australia fit? I suspect that P&O Australia's problem is its trying to sell and cheep and cheerful at a semi-premium price and its suffering because of that.
So what was the good stuff?
Great helpful staff; not too much up-selling; great entertainment; a plenty of room in the public areas; the speakeasy style bonded warehouse bar with great section of single malts; low and zero-alcohol wines offered in the dinning room; and a ship with guest laundry (MSC please take note!)
As this was a Princess ship we were able to grab a mini-suite, a great cabin lots of space and we could open the balcony door to my parents cabin next door. Great for socialising as we were travelling together. We were on deck 9, mid-ship so the cabin was very quite with cabins either side of us, above and below us and across the corridor. In other words perfect. The only minor issue was that balconies on that deck don't have a balcony or roof immediately above you so you are open to the sun and you can be seen from above. It didn't worry us but I know some people have commented on it.