My family (2 adults, 2 children 9-11) recently 27.09.13 took a cruise on the Carnival Spirit out of Sydney. We are regular Bali and Thailand holiday people, first time family cruises. We found the cruise overall a good holiday. Kids had a ball. Mum was sea sick for the first 3 days even without any swell. I was fairly happy with the cruise except for the alcohol prices (VB, New, Extra dry all $7.50. Pure Blonde, Crown, Corona, Stella all $8.25. Cocktails starting from $10.50).
The food was good and plentiful, we ate at the Empire restaurant every night and had breakfast and lunch at the buffet every day. The kids made the most of the 24hr pizza bar and also the 24hr soft serve ice cream. We did not get the soft drink package for the kids thought they would get enough sugar without that, plenty of free water and lemon cordial.
The entertainment was awesome the big band, jazz, Michael Jackson tribute shows every night. There were also comedians every night, early shows for the kids and two adult only shows later on.
We had a inside cabin was very cosy but that's what we paid for. I would recommend getting a balcony suite.