Well, i'll give you a few plus minuses from a general perspective:
1. All inclusive, no paying for anything except soft drinks, alcohol, the casino, and the upscale restaurants.
2. Visits multiple places. Cruises, unlike all inclusive resorts, are not stationary and provide an opportunity for a "taste" of several different ports
3. Provide multiple forms of entertainment each within a short walk of your cabin.
4. Provide extensive sports and fitness opportunities.
5. Provide a better social aspect as everyone is confined to the ship for the same amount of time. Throughout the week you will meet new people, but you will never say goodbye to anyone until the end of the week.
1. Some people might find ships restricting; not enough room for them resulting in a claustrophobic feeling
2. Seasickness may apply depending on the places you're sailing to, the weather, and the type of ship
3. Royal Caribbean lists a curfew for guests under 18.
4. Accidents are more prone to happen on cruise ships (people falling overboard)
5. Certain cruise lines require you to dine at a certain time.
1. Freedom of when to arrive and when to leave. Doesn't depend on a "sailing date".
2. Not restricted to a ship, facilities are often larger than those onboard a ship.
3. Similar pricing to cruises
4. More expansive choice of where to stay; many hotels and resorts are available.
5. Good for exploring one place for a lengthened amount of time longer than a day.
6. All drinks, food, and snacks covered at multiple restaurants
1. You are restricted to one island. No change of scenery
2. People come and go based on their dates; interaction with others will be limited.
3. Quiet, more relaxed environment may not be for people seeking a fun vacation.
Those are what I could come up with. Hope they help.