Mariner of the Seas receives generally positive reviews for its service, entertainment, and private island experiences, with many guests praising the friendly staff and enjoyable activities. However, some guests note that the ship is showing signs of wear and could use updates, and there are mixed opinions on food quality and value for money. Crowding in public areas and some maintenance issues are also mentioned. Overall, the cruise offers a fun and memorable experience, especially for families, but there are areas for improvement.