We chose NZ for our first cruise because we wanted to see more of the South Island. The round trip from Melbourne worked out well with same day flights from and back to Perth.
Golden Princess is an older ship but very clean and well maintained with lots of character.
The drop-off process for taxis and Uber was quite slow at the Port, we were glad we didn't have a meter running. Embarkation was good and we could go straight to our cabin. The bags were delivered a short time later so all very easy.
Our cabin had everything we needed, including a large wardrobe with lots of hangars (about 30) and room to store our suitcases. The air-conditioning worked well and we could adjust it as needed. Our balcony had two adjustable deck chairs and a small table and on Aloha deck there is nobody overlooking your balcony. The TV is large and you can take your own movies on USB and plug in. There were a few movie channels on TV which repeated on the same movie all day but there was no TV guide so you didn't know what time they would start/finish. Also several information and news channels. The bed was comfortable and there were plenty of drawers and storage.
Nothing special about Melbourne port
The grounds and gardens are lovely, we didn't go inside. Beautiful views.
We had lunch at Speights, the food was delicious and the beer and wine very good. Prices are reasonable, highly recommended.
The community volunteers at Gisborne were exceptional but there isn't really enough infrastructure for a cruise-ship visit.