With 15+ cruises on Carnival this was my first time on the Conquest. We did an 8 day Southern Caribbean cruise in a balcony stateroom. I think our dissatisfaction came from a combination of Conquest specific things and cutbacks made by Carnival since my last cruise two years ago.
Our cabin was fine-- a carbon copy of every balcony cabin I've ever had with Carnival but there's nothing wrong with that. Our cabin stewards, however, were nonexistent. They came in twice a day and did a fine job cleaning but I never met them once and couldn't even tell you if they were male or female. Usually there is some nice interaction, greetings, etc...
There are no more mints on the pillows, no more fruit punch on the lido deck or docks, and the Captain's cocktail party no longer had free drinks. We went to the steakhouse one night, which was very nice and had good food but were charged $2.50 for a Coke which we kind of thought should have been included in a $35 per person meal.