Passengers seeking more active pursuits will love the ship's three water slides (dubbed The Perfect Storm), two rock climbing walls, two surf simulators, ice skating rink, zipline and The Ultimate Abyss, a 10-story dry slide that plummets passengers down a heart-pounding ride through twists and turns with loud noises and flashing lights. Those who prefer more leisurely pursuits won't be disappointed, either. The ship has three big pools and lounging areas, an adults-only Solarium space, a relaxing spa and live music at every turn.

To help passengers really find the things they love, Harmony of the Seas uses a "neighborhood" concept, which first debuted on nearly identical fleetmate Oasis of the Seas in 2009. The idea is that similar areas or activities are grouped into neighborhoods. The ship includes seven neighborhoods: peaceful outdoor space Central Park; bustling amusement park style Boardwalk; the Royal Promenade for shopping, dining, drinking and dancing; Entertainment Place, for comedy, jazz and production shows; Youth Place, for the kids; Vitality Sea Spa and Fitness Center, for working out and getting pampered; and Pool and Sports Zone, for playing, swimming and being active. The neighborhood design is meant to reduce traffic flow, with the idea that people will naturally gravitate to the areas they love over and over again. And it does that, somewhat. So many activities are offered all day, every day, people will find their favorites. But when you sail with 5,497 passengers, you will never be alone. Harmony of the Seas is always busy, and when it's sailing in inclement weather, everyone moves inside the ship, avoiding the wonderful outdoor spaces.

The sheer size of Harmony of the Seas is astounding; it's easy to forget you're on a ship, especially when you're hanging out on the Royal Promenade, which feels resort-like. It also means you're less likely to feel the waves, a big plus for those prone to seasickness.

What Harmony of the Seas has in spades is variety, whether you're talking cabins, entertainment or dining. Even cabins in the ship's lowest category are thoughtfully designed and comfortable, with space for relaxing and plenty of storage. Likewise, the entertainment onboard, whether small scale, like an acoustic guitarist, or larger than life, like the production of "Grease," is simply outstanding. The ship's restaurants offer everything from low-key grab-and-go meals to multicourse, hours-long culinary extravaganzas. Quality is fairly varied, as well, and a number of the included restaurant options are just OK, while the venues that cost extra generally are very good. If you're going to splurge, dine at 150 Park Avenue. If you really want to go all-out, try the wine-pairing dinner there.

Children's facilities, especially when combined with the number of activities onboard, are virtually flawless. You'll find lots of space for kids of all ages, fun and entertaining programming as well as a partnership with DreamWorks that makes movie time a blast. Parents can spend time playing with their kids all day, then feel comfortable heading off on date night knowing their children are in good hands.

Service onboard is a bit spotty; brilliant in some venues and apathetic in others. Likewise, lines at the guest services desk get long quickly, and problems aren't always promptly resolved. Phone calls to guest services or restaurant venues often go unanswered.

The Ultimate Abyss slide, certainly the most talked-about feature on Harmony of the Seas, perfectly encapsulates the ship: It's innovative, fun, bright, exciting and slick. While the slide -- and the ship -- aren't for everybody, those who love high-energy activities and action will be in heaven.