As others stated, the embarkation and debarkation processes are pretty smooth. We were on the ship by 11:30am and most were off the ship before 9:30am after we returned.
The decor was not as loud as some ships, but we had to laugh that they decided to glue circles onto lights, glass windows and glass walls....many are now missing and it looked a bit shabby.
The balcony room we had was roomy and fit the 4 of us just fine. We had plenty of room for our stuff and storage for the luggage (7 pieces!) The "lip" at the bottom of the shower is too short so there was a flood in the floor every time we took showers. We tried everything from turning the water pressure down, facing the shower head to the inside of the shower, and getting a longer shower curtain. Nothing worked so keep things off the bathroom floor. Our room steward, Gedi (pronounced GeeDee), was very good and knew each of our names from day one. The hair dryer is not very good so if your hair is long and takes a while to dry as ours do, bring one from home.
The breakfast food is as one would expect, yet the cold "gravy" to put over biscuits had me gagging. The lines in the buffet were long as others state, however after waiting to get to the food, the choices were slim. Lunch was not very good each day and led to many afternoons spent at the Pizza counter instead. We did have the Mongolian grill one day and they cooked everything just fine, but the sauce choices didn't include the normal teriyaki, Mongolian, or soy sauce so my niece only had black bean sauce as a non-spicy option. We did not try the pasta bar or burrito bar since the lines were longer and that could be because others found that as their only edible option besides pizza for lunch. There is a BBQ place on deck 5 that is only open a few times during the week....good stuff. Dinner in the dining rooms had a few items that were tasty, but honestly it was pretty disappointing. I know they are cooking for massive amounts of people, but we honestly were unable to eat some of the food. The steakhouse was booked solid early in the cruise so we did not get to try their food. Service in the buffet area was hit or miss. We were asked if we wanted juice or coffee one morning and other times, some of the people would look away when they passed a table full of dishes.
We had been to Cozumel 6 times before so we did not do an excursion, however for the first time ever, we were chased down and pulled aside from different men over and over stating they were working for the "city" trying to get us to go to a hotel (seemed like a time share, but we did not listen long enough to find out for sure).
We have been to Belize before and had planned to not get off in Belize with all of the warnings and issues they had recently, but those who got off and did excursions through the ship seemed to have enjoyed their time.
We loved Carnival's Mahogany Bay Beach in Isla Roatan, Honduras. It is basically a beach, however you were able to go on pedal boats, kayaks, and surfboard like things with ores (didn't try those). When laying out, it was nice to have Fat Tuesday servers coming around to get drinks or food for you. They had shady spots, sunny spots, and "clam shell" beach chair covers...something for everyone. We took the beach chair lift over to the beach just because the kids wanted to, but it wasn't worth the $31 for the 3 of us unless we would have rode it a few times just for the fun of it. :)
Costa Maya was new to us so we did not know what to really expect there, however when you got off and walked into the port area, there was a pool there with a swim up bar, beach chairs, etc. that seemed to be a big hit. We did not happen to have our suits with us, but it looked inviting!
We enjoyed the comedians and took the kids with us to the family friendly shows at 7:30. We also liked the showtime shows through out the week. There was one singer in the lobby area that we found to be pretty bad.
Our kids were in the Circle C and O2 age groups. These groups are older and can come and go as they please. They did have certain scheduled activities for the kids, but this was normally from 9pm to 1am. Many of the younger kids were upset when having to leave their kid groups so that seemed to be a good sign as well.
On sea days, the beach chairs on the deck 5 lanai are excellent if you get the ones on the side facing the sun. This is where the hot tubs are as well. We found this to be a nice quiet place to get some sun, read a book, etc.
NOTE: While I am not a smoker, you can smoke in some outside areas on the PORT side of the ship. We heard many people complaining that people were smoking, but if they had realized that it was always on the Port side, they would probably have had a more pleasant experience.
I am not sure if I would be willing to book another Carnival cruise...after 3, we have the same so-so feeling when it's time to get off.