We've taken somewhere between 13-15 cruises (kind of lost count) and have sailed on Carnival multiple times. We chose this cruise because we were celebrating a birthday that week, but our schedules couldn't accommodate a 7-day cruise, so we booked the Monday through Friday itinerary.
We are late 40's/early 50's and sometimes behave more like 30-year olds. We enjoy socializing and having a few cocktails and I would say we are pretty laid back. We enjoy our vacations and try not to let the little stuff get to us. Our fellow passengers seemed primarily to be a mix of late twenty somethings to mid forty somethings, with a little of every other age group mixed in. We found most of the other passengers to be very nice, polite and social. It was not a school break so there were only a handful of children on board that we could see.
The cabin: I was a little apprehensive because the ships that sail that itinerary don't have many balcony cabins and we haven't sailed without a balance since the 1990's. I'm happy to report that I didn't miss it. We had a portrait window that offered tons of light and I never felt claustrophobic, plus the window sill makes a great shelf. The cabin otherwise was just the same as most we have had in the past except there is not a little sofa. Plenty of storage, desk space and adequate bathroom. Shower actually had really good pressure once you get the hang of the temperature adjustments.