I just got back from a week on the Carnival Magic, completing an Eastern Caribbean cruise. Over spring break, I completed my second cruise on the Disney Dream, with both of them stopping at Nassau and
Castaway Cay. It is worth mentioning that my family had this cruise paid for by my mother in law, and that we would have never sailed on Carnival if we were spending our own money. This is because of the perception of Carnival that we had going in to this past cruise. The Dream and the Magic are around the same size and age, so I figured a comparison would make sense here.
Embarkation - The Carnival one went much, much quicker. When boarding the Disney ship, we waited in a security line for 40 minutes, and then a check in line for another 20. By the time we had gotten through both, our boarding number had already been called. When boarding the Carnival ship, we breezed through check in and security. We ran into a minor hiccup when some teenager who was checking tickets didn't know how to process our children, but it was quickly fixed by a supervisor. The whole process from pulling into port to walking onto the ship took about 15 minutes.
Disembarkation - They seemed about the same to me. It's just hard to get thousands of people walking off of a ship and through customs, and I felt that both lines handled it the best they could.
Ship Layout - The Disney ship's layout made more sense to me. Everything flowed through the grand atrium and it's connected hallways. The Magic has dining rooms on the 3rd floor, but the galley was also there, cutting the floor into chunks. The only way to get from the front to the back easily is to go up to the 5th floor, where a lot of the nighttime entertainment spots are found. In order to walk through that deck, though, you have to walk through the casino, which allows smoking. After having to do that a couple of times, my family quickily memorized which elevator bank we had to go to in order to get to each section of the ship (dining room is in the middle, go to the middle elevator first, then go down. Coffee is towards the front, go to the front elevator, then down, and so on.) Once we had the layout figured out by night 3 or so, it was fine. The middle elevator section was really neat, as there were glass elevators overlooking the atrium on deck 3 all the way up to deck 11. It made that area of the ship feel very "grand".
Cleanliness - Disney gets a big win here. On the Disney ship, there were people actually in the bathrooms cleaning them as they were being used. There were people wiping down railings during the day. There were other people standing at the entrance of eateries almost forcing you to use hand sanitizer. The bathrooms on the Magic were never dirty, but they were more similar to one you may find at a restaurant, clean, but clearly used, with water on the floor, etc. The railings on the ship were sticky at points. Most upsetting was the hand sanitizer at meals. It could be found in dispensers attached to walls. A few people would use them from time to time, but many would not. The one in the back of the ship, by the pizza place, was not working when I tried to use it. I observed people swabbing decks between 6 and 7 in the morning, so the Magic was cleaned, just not as frequently as the Dream. The Magic was never dirty, but it was clear that some of the extra money people spend on Disney cruises does go towards hiring more cleaning staff.
Staterooms - This was by far the weakest point of the Carnival Magic. Despite being around the same age as the Dream, the Magic's rooms felt old and used, while the Dream's felt a lot more like hotel rooms. The best comparison I can give is that the Disney rooms felt like staying at a smaller version of a Disney hotel while the Carnival ones felt like staying at a Motel 6. Functional, but not something I wanted to take pictures of. There was a layer of grime on the balcony that grossed me out on the first day, but that I learned to just live with by the time the cruise was over. The sink in our room backed up. We reported this on our first afternoon, and nothing was done about it the whole week we were there. We had a major issue with air conditioning, which I will go into further detail about in the staffing section.
Staffing - Everybody I interacted with on the Disney ship seemed like they were in the customer service industry.
Most of the people I dealt with on the Carnival ship seemed the same way. It felt like the lower level employees on both ships were very overworked. I felt like the ones on Carnival were trying to please customers almost against their bosses' wishes, though. When we made friends with bartenders, they would tell us about new drinks and encouraged us to try them based on our interests, but would have to pretend to make something different because they were being recorded as they worked. Our room on the first night was very, very warm and stuffy. I tried calling housekeeping, guest services, and even room service at about 10:00 that night. The only reason I tried so many people is because not a single one of them would answer the phone. The next morning we had to walk down to guest services, only to be told that as long as our room got down to 74 degrees, it was acceptable, whether we liked it our not. I thought that was pretty poor customer service. If I was asking for the room to get down to 58 degrees, of course I could understand, but the hardline set at 74 felt cheap to me. Luckily, my room steward knew the room slept hot and was able to remove the grate to our vent, increasing air flow. It felt like he was Mr. Incredible working for Insuricare, working to please customers against his bosses' wishes.
The dining staff on the Magic was much more fun and interactive in my opinion. This is taking nothing away from the Dream's staff, and comparing one dining staff on one cruise to just two staffs on the other line does not in any way make me an expert, but I thought it was worth sharing that opinion.
Food - Without a doubt, the food in Cabanas on the Dream was much better than the offerings in the Lido deck on the Magic. The food offerings at Cabanas were both solid and varied and I always found something I liked there. In the Lido marketplace, it was often the same food every day, and some of the items tasted like they had been sitting out for some time. I also thought that Cabanas was better thought out. It had many smaller stations, which broke up crowds. The Lido marketplace had 4 large serving stations, so during a rush it led to large lines. The Magic's other food offerings were better than the Dream's, though. They had a really good burrito place, a very popular burger place, as well as an Indian food stand and a smoked meat stand which were both very tasty. My only complaint about those places was their limited, and somewhat odd, hours. They were often only open from 12-2:30, even if the ship was docking at 11:45. This made many of those locations worthless if you planned on spending the day ashore.
The sit down restaurant on the Magic was much, much better than Disney's offerings. When I was on the Dream, I struggled to find any one dish at each meal that would excite me in any way. I remember the Cranberry salad at Animator's Palette being one, but then the rest of the meal was average at best. On the Magic, every item I ordered at every meal, with the exception of a total of one entree and one appetizer during the whole week, was exceptional. My wife, who typically does not get excited about food, agreed.
The dinnertime entertainment was also surprisingly more fun on the Carnival ships. As neat as it was to look at little Beast heads, or to see flowers open and close on the Dream, it was more entertaining to see waiters and dining guests get up and dance to "Can't stop the feeling". I never realized how stuffy the Dream's restaurants felt until I experienced my meals this past week.
Pools - I liked the Magic's pools better. It is worth noting that the adult only area on the Dream is much better than on the Magic. The pool with the swim up bar is much more fun than the few hot tubs and sunning deck found on the Magic. That did not bother us, though, as we had two children with us at all times. The Magic had 2 pools, a quiet one in the back of the ship, and a "party" one in the middle. This was comparable to the Dream's pools. The kid's water play area was much, much better on the Magic. It had two great water slides, buckets dumping on kids, water cannons, racing slides, and, most importantly, supervision by staff members. I hated that Nemo's Reef on the Dream because it was both difficult and necessary to supervise children there, and many people chose not to do so themselves.
Entertainment - Disney gets a big win here, but with a cost. It would be pretty impressive for somebody to top having guests watch Beauty and the Beast, and then having Goofy and Pluto giving out autographs after the show. I actually preferred my evenings on the Magic, though, because of the lower level entertainment. On the Dream, we felt such pressure to make dinner by 5:45 so that we could get seated and then go to the 8:00 show. While it was worthwhile on some nights, it left us feeling too pressured on others. With the entertainment on the Magic not being a constraining factor, we were able to enjoy the anytime dining. If our kids were up from nap early, we ate early. If they were tired, we slept late. It felt much more like a vacation. After dinner on the Magic, we would either go up to the pool deck and catch the end of a movie, enjoying the free popcorn, or we would drop the kids off and at kids club and my wife and I would enjoy one of the many bars on the ship.
The bars on both the Dream and the Magic are pretty on par with each other. I really enjoyed the skyline bar on the Dream, and the Redfrog Pub on the Magic. It felt like both ships had something for different types of people. The kid's clubs on both ships did a good job of entertaining our kids for 40 minutes at a time. There was more to do on the Disney ship, but that's not necessarily a good thing, as that led to our kids jumping from one thing to another and then getting bored. The kid's club staff on each ship was great.
Despite the many negatives of the Magic, I would book another cruise on it in an instant. In fact, I am already looking into taking another cruise on it's sister ship, the Breeze, next summer. The real draw of the Carnival ships is the price. I was not able to enjoy my most previous
Disney cruise because I was dumb enough to break down how much it cost per hour. If I did the same with the Carnival Magic, the cost is not nearly the same. The people on the islands don't care what ship you took to get there, or how much you spent on your stateroom. The Carnival Magic, to me, was like staying at Pop Century in order to enjoy the parks. There was some big downsides to it, some really good upsides to it, and overall it was a lot cheaper than staying at the Polynesian. Both ships take you to islands, which is the real draw of a cruise, just as both hotels get you to the theme parks. My weeklong cruise on this ship completely changed my opinion of sailing on Carnival. I was almost glad to see some of the issues, as I knew the line was not perfect, and it made it easier to enjoy all the great parts of the ship.
*A couple of additions that I should have mentioned earlier*
The coffee at the coffee bar on the Magic was fantastic. If any coffee drinkers take a cruise on the ship, try the frappe. It isn't overly sweet like ones at Starbucks, and everybody I knew who tried one ended up ordering another at some point on the cruise.
I was nervous about going on a Carnival cruise because I had a preconceived notion that there would be a "people of Walmart" (to use another stereotype) sort of crowd on the ship. While it was definitely a more casual crowd, every other cruiser I interacted with was very nice to myself and my children. Lot's of retired couples could be found on this cruise, probably because it is a relatively cheap getaway.
Part of my nervousness about the people came from the fact that you could prepurchase 15 drinks per day as part of their "Cheers" package. I envisioned a bunch of obnoxious drunk people all cruise long as a result of this. Other than one really annoying guy who kept yelling "woo!" dozens of times in the main pool on the first day, I was never bothered by anybody else. I actually got the package myself and never had more than 6 drinks throughout a day, but liked how it was similar to the
Disney Dining Plan in that it allowed me to try drinks I would have never tried before without worrying about their price. I would get the package on my next Carnival Cruise.
I have no desire to cruise Cunard for example, but some folks probably love it. 
