Celebrity Millennium receives high praise for its exceptional service, friendly staff, and memorable itineraries, especially in Alaska and Asia. Guests consistently highlight the crew's attentiveness and the quality of the main dining room food. However, some reviews note that the ship is showing its age, with occasional maintenance issues and outdated accommodations. Entertainment and activities are generally enjoyed, though some guests find them lacking compared to newer ships. Pricing is seen as fair, but add-on fees and specialty dining costs are a common complaint. Excursions and ports are often a highlight, though some guests desire better descriptions and organization. Internet connectivity and crowds are mixed, with slow Wi-Fi and occasional overcrowding in public areas. Overall, the Millennium delivers a strong cruise experience with room for improvement in ship updates and specialty services.