Our 3 kids (ages 12-14) absolutely loved Circle C on our recent cruise on Carnival Elation. They made new friends and counted down the minutes until Circle C events began. Although the events were structured, there were short intervals of unsupervised time (i.e. scavenger hunts, ice cream breaks). Our kids had walkie talkies so they could locate us as soon as events finished as they were not permitted to roam the ship outside of Circle C activities. There were some groups of kids roaming the ship and wreaking havoc (running, yelling, smashing ping pong balls, knocking over all the giant chess pieces). Some parents seem glad to take a vacation from their kids so they let them roam free to spoil other's vacations. This is a risk you take when booking on a "family fun ship". I would book Carnival again for our kids, but if vacationing without children, my husband and I enjoyed our Royal Caribbean experience more as it was an older crowd and more relaxing.
Service in the dining room and cabin was exemplary, as usual. The food was very good, but not the exceptional experience we had on other cruises. We absolutely loved the "Your Time Dining" option and never had to wait for a table. Unless you're on the ship's dining schedule, you will often find buffets are closed and the service at the 24 hour pizza bar is consistently slow. We walked away one day after waiting 5 - 10 minutes with no one appearing to serve the crowd that had formed. Our kids enjoyed the pizza and had more patience for waiting.
Entertainment did not live up to our expectations from past cruises with the exception of Mutzie, the comedian, who was top notch, and Bruce, the pianist in Duke's piano bar whom we wished we had encountered before the last night. He was fantastic and very engaging with the crowd. Music Power was also a fantastic band who played in various locations most nights.