Mariner of the Seas receives generally positive reviews for its service, entertainment, and overall cruise experience, with many guests highlighting the friendliness and helpfulness of the staff, enjoyable activities, and memorable excursions, especially to Coco Cay. However, there are recurring criticisms regarding the ship's aging condition, food quality inconsistency, crowded public spaces, and extra charges for amenities. While many guests had a fantastic time and would recommend the ship, others felt that the ship needs updates and that Royal Caribbean's value has declined compared to previous years.