We actually did most of Australia, joining the cruise in Perth, followed by a back-to-backcruise to New Zealand. A total of 30 days. What we have discovered over several years of cruising is that cruise success is tied to the Captain. The tighter the ship, the better the cruise. This ship was well run and the crew was awesome. And a change of Captain 3/4's of the way through didn't change things.
This was our first time in a "Sea" Class Princess ship. Total passengers 2000, average passenger count 1900. Our opinion is that the public areas are too small. Inside cabin passengers tended to sit in the bars and read, blocking others who wanted bar access. To be fair it was cool in NZ so sitting outside wasn't always an option.
We had a basic balcony room which seemed small to us. Our room attendant was great though, and we enjoyed our balcony.
Our cabin seemed small to us. It was well appointed, but on this class ship most spaces seemed small to us. FYI, we prefer smaller ships, no more than 3000, but this class ship just feels small.