My wife and I (mid 30s) recently took the 8 day Southern Caribbean Cruise (3/1/12 - 3/9/12) on the Carnival Miracle. Kind of a second honeymoon. Though we travel together often, (as I enjoy her company, which I find best for the marriage) neither of us have been on a cruise in our lives.
Carnival did the big picture things really well for us. Food, in particular, seems to be the area most of concern for review seekers and writers. I found it pleasantly surprising in all terms of variety, availability, and quality. We are not really picky people, though. I have extensive experience in the food service industry, so my expectations are usually tempered. I was quickly impressed. My wife was occasionally disappointed in the temperature of the food itself (she was right), but being primarily buffet (even the Bacchus room is a fancy buffet service), there's very little you can do about that. They weren't using real eggs or butter, the hallmark symbols of some serious food coming your way. But, as far as needing to feed thousands of people every eight hours, I was seriously amazed at the amount of quality and variety they were able to offer day after day. For instance, my favorite dish all week (we ate all over ports and paid additional for a night at the Miracle steakhouse, Nick & Noras) was an appetizer at the Bacchus; Smoked Duck with Pomegranate reduction over Thai Rice Noodles. It blew my mind.
Another thing Carnival does well is people. Our steward, Fernandy, knew our names without us even introducing ourselves and called us by them every time he saw us. He was quick to answer questions, even ones not related to his specific job. We absolutely qualified the level of service we got as "borderline creepy". It seems we would go to breakfast and come back to the room to prepare for the pool or an excursion and the bed would be made, the bathroom like it did when we first opened the door. We went to breakfast at all hours, too. Like I said, kind of creepy. Servers at the Bacchus were pleasant and attentive, almost offended when you didnt eat. We had occasional general quasiness from the boat, not nausea or anything. Just some nights, you didnt feel like eating an entire half rack of ribs. I did mention the situation to the waiter when he asked, and he was quick to bring fruit and sherbet to the table, which really helped.
The room itself was half awesome and half a problem. My review might not help you since it seemed we got a jack of all trades kind of room. Giant bathroom for a handicapped person, but the bed was like two fancy cots put together. The pillows were probably real nice if you sleep on your back, but I sleep on my side and literally felt kind of choked trying to use it. Usually when four pillows are in a hotel bed, 2 are soft and 2 are firm, but these were all basketball shaped marshmallows. We saw an advertisement on the TV that the towels, and bathrobes were for sale and we were considering it. But then the mattresses and bedding were for sale too and we both burst out laughing. The TV itself also was like someone had the turned the brightness all the way down and there was no way to fix that. Not that we watched much TV, but some people might like to not miss shows or feel at home for a night. But the balcony is where we spent most of our time in our room, because what we got was exactly what we wanted there.