My wife and I had been on 2 cruises before, in Bali in 1998 and up the east coast of Australia in 2003. We had enjoyed them so much that when it was our 40th wedding anniversary we decided on another cruise.
Carnival Spirit was everything (almost) that we had hoped for -- large, wide variety of bars and lounges, very good food and lovely staff / crew. All in all, we had a great time and would do it again, in fact, probably will.
A few pluses and minuses: for me, physical fitness is a must, and I have used a Concept 2 Indoor Rower to train on for the last 15 years, since marathon running destroyed my knees and can no longer run. I was extremely disappointed to see Carnival Spirit had no rower in their otherwise very well appointed gym. My 2 other cruise ships both had plenty of rowers. Secondly, we were disappointed with the lack of late night activities for genuine night-owls -- only the nightclub, with its awful techno-dance rubbish music and the 24 hour pizza seemed to be open. The wonderful Club Cool with the superb rock band "Music Manila", closed at 12:30am leaving us nowhere to go, and we did not want to go to bed!!! I would seriously suggest a jazz / wine bar to stay open until say 3am. Other passengers agreed with us on this point.
A bit too small but not tiny. Air-con not keeping air fresh at night so slept with french doors open. Shower was lovely. Cabin was quite quiet. Stewardess was lovely and room kept clean and tidy for us. Only one power point so taking a powerboard is a good idea.