Hubby and I have been on two cruises and loved both of them. FWIW, one was our honeymoon cruise (Carnival Sensation to Grand Cayman, Cozumel, and New Orleans in 2001) and one was last fall (Royal Caribbean Mariner of the Seas to San Juan, St. Martin/San Maarten, and St. Thomas).
Whether or not you like a cruise will depend on what you are interested in. My brother is a big drinker, so cruises are not for him - you have to pay for your alcoholic beverages, and the prices are comparable to a bar or restaurant. For him, all-inclusive land vacations are best. Hubby and I are laid-back and like to relax, lounge, and eat. So, cruises are great for us. We like the idea of seeing a little bit of a lot of places. Plus, you can “try out” a destination before deciding to stay for a long time. You can book shore excursions through the ship or with an on-site provider, or just wander on your own (the amount of wandering recommended in any port will certainly vary!).
On our first cruise, we swam with sting rays in Grand Cayman (booked with an on-island company), toured the Mayan ruins of Tulum in Cozumel (booked through the ship to ensure a timely return), and just wandered around in New Orleans on our own. Our second cruise’s itinerary was affected by Wilma - we were supposed to do Grand Cayman, Costa Maya, and Cozumel, but had to change to the eastern itinerary. So, we had no excursions booked ahead. We walked around San Juan and did some shopping (we only had a few hours). We had a great time on St. Martin/San Maarten - we took the local bus across the island to Marigot (on the French side) and found an empty beach to lounge on and then took the bus back to port and did some shopping. We made a short visit to St. Thomas because I had gotten dehydrated on St. Martin, and wanted to take it easy.
The quality of the food, drinks, and service will vary wildly depending on what cruise line you choose, as well as on-board activites and amenities. There are loads and loads of cruise lines, and each one caters to a slightly different clientele. Disney is great for people with kids, but Carnival and Royal Caribbean are family-friendly as well. Holland America, Norwegian Cruise Lines, Princess, and Celebrity are little more “high-class” than the first three. Some ships are gigantic and hold well over 3000 people - others are much smaller.
The Mariner of the Seas is a fairly new ship and it’s huge. There are three pools (one adults-only), six hot tubs (three adults-only), a fitness center, an ice skating rink (open certain hours), putt-putt, a rock wall, in-line skating, a library, a movie theater - lots of stuff to do. There’s a casino and a “street” of shops, as well as at least six bars (wine/martini bar, pub-style, salsa club, dance club, and the Schooner Bar). And, plenty of places to do nothing, should you choose.
They provide a wide variety of entertainment options too. Yes, they have the Vegas-style shows each night, but they’re different each night. We went to see Bowser (from Sha Na Na) and the 80s show - both were well worth it. They have comedians and ballroom dancing and karaoke and guitar players. And then there’s the ice show - it was much much cooler than what I expected to see on a ship, especially considering how small the skating rink is.
Plus, food is available 24-hours a day.
For more info, check out the message boards at Cruise Critic. The site’s been around for ten years and has loads and loads of info.