I will note that our cruise was an Atlantis cruise (a gay cruise charter) and so I am unable to review certain elements that were provided by Atlantis, rather than Carnival.
Embarcation: We paid for the "Faster to the Fun" upgrade and were able to bypass the line. I can't suggest this enough. Carnival's embarcation process is as dehumanizing and stressful as a TSA checkpoint on the Wednesday before Thanksgiving. People stood in line for three hours. Some people almost missed the ship even though they were there two hours prior to departure. Staff were rude and pushy and barked orders at us if we so much as took a wrong step. I certainly would expect better of a company that operates these cruises on a weekly basis.
Physical Accommodation/Cabin Amenities: The ship is comfortable and stable. Air conditioning in the cabin keeps them very comfortable even in very hot and humid weather. The cabins, while smaller than a standard hotel room, are spacious enough. Our extended balcony faced aft and offered us a small "extra room" when one of us wanted to watch TV but the other wanted to just read. Water pressure was good and both hot and cold water were readily available (although our sink's cold water was a bit of a trickle). There is a mini-bar that is freely accessible (in case you need to bring any refrigerated medications or such). Our cabin was located at the extreme rear and there was a bit more movement so far from the ship's center of gravity and a small amount of vibration from the propellers/diesels, but this actually helped me sleep. My only complaint is that the main lights in the cabin are achingly bright, but there are smaller lights that can be turned on to offer a less actinic glare.
Decor/Public Rooms: The decor is almost impossible to describe, but it is absolutely *hideous.* There is an eye-watering cacophany of clashing color, bizarre fixtures, nonsensical themes (a Spartan warrior here, a pirate captain there, Atlas holding up a light fixture over here, a reference to Dr. Strangelove over here, lights that look like multicolored pepper grinders hanging from the ceiling, random faux-Italian frescoes). We couldn't stop laughing at it. That said, once embarcation was over, we didn't feel like the ship was crowded (it felt really crowded during embarcation, but that's to be expected). Elevators usually came quickly and made minimal stops. There were adequate whirpools (although the ship could use one or two more). The gym is nice, but lacks open floor space for stretching. The theater is nice, but the decor is distracting from the show. I don't use the casinos.
Entertainment: Was organized by Atlantis, not Carnival. So I won't review it.
Service: Our cabin steward was top-notch, friendly, personable, and quickly learned our habits. They make the keeeUTEst little towel animals for you to find at turn-down. On the other hand, dining room service was spotty. I once ordered a drink and it was delivered when I was almost finished with the main course. Sometimes appetizers were delivered only seconds before the main course and then the waiter would have to vanish with the main course only to bring the now-lukewarm dishes back later. The other REALLY annoying thing was the bar waiter. On one night, I was pestered four times IN THE SAME MINUTE by four different waiters about whether I wanted a drink. And when I say "pestered," I mean tapped on the shoulder and conversation interrupted. It was extremely annoying and they have no way to signal to other waiters that a given table is not interested in a drink right now. The service was so obtrusive that I actually complained. Apparently a lot of us did and it got better on subsequent nights.
Shore excursions: We only did the Eco-Snorkeling in Cabo San Lucas, but it was quite fun if you like snorkeling. Saw a lot of cool stuff. I heard fantastic things about the zipline adventure in Puerto Vallarta, but we didn't do it.
Food: Ranged from adequate to at times wholly inadequate. It was cheap, often swimming in greasy gravies and there were very few healthy options. Fruit was often under-ripe and melons sometimes still had bits of rind attached, while pineapple slices weren't even cored. Tomatoes at the salad bar were over-ripe and almost inedible. The dining room food was slightly better, but still unpredictable and the portions were small. There was one night where I went to bed hungry because the food was so inadequate that I couldn't eat it (and I promise I'm not a picky or snobby eater).
I cannot recommend this ship and next time I will be happy to pay a bit more to enjoy a better experience.