I've cruised once on
Royal Caribbean, four times on Carnival, and I just got off my first
disney cruise on the Wonder last week. My husband and I don't have kids, so just two adults ages 27 and 29. Of co
urse we had to compare everything between our experiences and we decided that the food overall was better on Carnival. We had three outstanding meals on Disney, a Palo brunch, an embarkation lunch buffet, and the first night's dinner. Other than those select meals, the food was not as good as Carnival. And Disney's food is good, so that tells you Carnival is delicious. I've heard Norwegian has the worst food, not bad, just not as good as the others from a cruiser who's cruised all the major lines.
We noticed there was way more stuff to do on the Carnival ships whereas on Disney there were several times when nothing was planned, there were just blank gaps in the navigator. The cabins on Carnival are slightly larger than Disney. I love afternoon tea on Carnival and was sad there wasn't anything similar on Disney. They serve tea on sea days in one of the dining rooms and have accompanying tea sandwiches and desserts. The cucumber sandwiches are amazing! There is always something going on from trivia to towel animal folding classes.
The shows on Carnival are not nearly as good as on Disney, but who can compare with a company built on entertainment. The comedy is hilarious, you will leave there hurting from laughing too much.
The adult Serenity deck are is lovely and peaceful. If you go on a ship that has it, you'll love it. All the Carnival ships have an adult only pool and area, but the ones with Serenity are great.
I've cruised on Carnival Destiny, Spirit, and Splendor. They are three different class ships and I enjoyed them all. I'm not sure when you're planning this trip for, but Destiny is going in for a huge overhaul and will re-emerge as Carnival Sunshine.
Our final thoughts are that based on experiences had on both cruise lines, we'd pick Carnival 100% of the time without kids. We don't have kids yet, so I'm not sure if that will change when we do. The shows and movie theatre on Disney were awesome, but other than that, they're not that different and Carnival is usually about half the price of Disney. We're DVC members, so if we weren't trying to use up points before they expired, we wouldn't have gone on Disney because of the price. We loved our Disney cruise, but we would rather use that extra money for something else, like another cruise
Also, if you're a drinker, the drinks on Disney seemed to be about 5-6$ each and you can bring your own liquor on board. On Carnival they are slightly more expensive, 6-9$ each and you can only bring 1 bottle of wine per person. Just an FYI. Although if you're looking to bring your own liquor, there are whole threads on cruise forum sites about how to get it past security.
If you have any questions about the differences or anything more specific, let me know, I'm glad to help. I'm a cruise addict. We did the Mexican Riv on the Splendor in Jan, just got back from Alaska on the Wonder, and I'm now planning my next Caribbean cruise for Feb on either Carnival Magic, Dream, or Breeze. Can't wait!!