Mariner of the Seas receives generally positive reviews for its friendly and hardworking staff, enjoyable entertainment, and fun excursions, especially to CocoCay. Guests appreciate the ship's amenities and activities, making it a great choice for families and groups. However, there are recurring criticisms regarding the ship's aging condition, crowded public spaces, inconsistent food quality, and extra charges for certain services. Some guests also noted issues with cabin cleanliness and maintenance. Overall, the cruise offers a fun and memorable experience, but there are areas that could be improved to meet the high expectations set by Royal Caribbean's reputation.