We've never been on a cruise before and thought the idea was a good one since Carnival featured several groups for kids. Mine are 14 (F) and 17 (M). If you've got teens, you know its a real challenge to keep them engaged and not "so bored they could die." Mission accomplished. Both kids had a blast. The 17 year old met with the "O2" (15-17 yr olds). They had their own club (supervised) and I barely saw my son after the first night. Carnival had scheduled events but also a lot of hang out time. My 14 yr old LOVED the Hollywood dance club. Almost every night Carnival had a dance for "Circle C" (12-14 yr olds), often w/a theme (big hair, 80's, etc). They also made T-shirts, played games, and more. We felt safe allowing the kids to roam around on their own.
As a family, we really liked that Carnival offered something to do almost around the clock. If you choose the Triumph, I recommend you don't miss the Showtimes (8:30 or 10:30pm)--a variety of Vegas style shows and comedy events. The dancers were true professionals. The Comedian Eddie Capone was funny and had a little give and take with audience members. The Magic Show with Kevin and Caruso was great too. ON the final night, your fellow cruisers perform--hilarious!
On the other hand you could choose to do nothing and just relax. Nice.
FOOD: We ate at the South Beach Buffet on many occasions. Cafeteria style, good food. I recommend going to the dining rooms for dinner (either the London or Paris rooms). I wish I would've figured that out sooner. Crank up the ratings for food 10 times--from good to Outstanding! For first time cruisers: all of this is included in the price of the cruise package. ADVICE: get fit before you go. You can eat anytime, as much as you want, and may gain a few pounds (ice cream all day).
DRINKS: Alcohol--Expect to pay restaurant prices. The Cheapest glass of wine was $5.25 (Woodbridge Cabernet) and the cheapest beer was Coors Light at $3.75. How to drink cheaper: buy wine by the bottle ($22) and beer by the Fosters Oil can ($5.95). You can't buy bottles at your destination stops and expect to drink it on the ship. You must surrender it upon boarding. The water and soda in your room is not complimentary; if you open it, you'll get charged for the drinks ($1.75 can of soda, $3.50 for a large water). Unless you or your kids drink gallons of soda, don't purchase the bracelet for sodas. Juices, water, & coffee flow all day at no additional charge from dispensers.
STAFF: In a word, wonderful. Every single person was friendly, helpful, and smiling. Cruise director, Matt Ross, rivaled the comedian for laughs.
MUSIC: if you like 80's Rock, you'll love the band "Music Power." All the members are from Asian or Pacific descent. I expected versions of songs that sounded like singing in the movie "A Christmas Story" (i.e. Fa rah rah rah rah). Bu these guys were absolutely excellent!! The guitarist easily cranked out Van Halen, Journey, Def Leppard, etc. The singer could hit all the high notes of Steve Perry--not many can. Visit all the bars for live music (sing along with Eric at the Piano Bar, hit the Lido Deck for Calypso music, go to the Club Rio for Karaoke, and the Oxford for cigars and jazz or classical).
DESTINATIONS: we stopped at Half Moon Cay (pronounced like "Key"). This was the most pristine beach I've ever seen. This is the one you want for swimming. St. Thomas was beautiful w/a lot of shopping stops (esp. for jewelry). My son and I went snorkeling at Buck Island (a turtle reserve) on "The Fury" --booked it in town and saved $. San Juan, Puerto Rico: took the family (at only $20 p/p on a tour of the city, the Capital, a historical Fort and the shopping district--get off the ship and there will be folks at the end of the port who will take you. Otherwise, you can book the same thing on the ship for nearly double the cost). San Juan was too busy for our liking. Loads of junk stores available to waste your money. Grand Turk: the beach was cool for snorkeling ($16 equipment rental) but not the best for swimming--very rocky lots of sea grass. Walk through Margaritaville quickly or your money will evaporate (two mixed drinks = $20). Enjoy the pool for free. Wave runner will cost you $24/hr.