We went on our first cruises this year. It was for a 60th birthday for a close family friend with a group of 20 people. It was a blast. Other than challenges with the luggage, the over all experience was absolutely superb.
We weren't prepared for the cruise as we had over packed clothes and shoes. We were up set that we weren't allowed irons on board, but to be fair the laundry was provided as a complimentary service - at lease we know for next time.
We enjoyed the islands - although Labadee was a bit too hot for us.
The last thing I'd like to say is that every thing on board is quite expensive so be prepared to pay $3.50 for a regular bottle of water (and an 18% service charge will be added to your bill for every service). So ensure you register your credit card - as it makes life much easier.
All it all we enjoyed our experience, It has made us catch the cruise bug and we will definitely go again.