Celebrity Millennium receives high praise for its exceptional service, friendly staff, and memorable itineraries, especially in Alaska and Asia. The food and dining experience is generally well-regarded, though some guests found the buffet and specialty dining lacking. Entertainment and activities are mixed, with some guests enjoying the shows and others finding them limited, especially for younger adults. Cabins are clean and comfortable, but some are dated or have maintenance issues. The ship is noted as older, with some areas showing wear despite refurbishments. Pricing is seen as good value by many, though some dislike the add-on fees. Excursions and ports are highlights, though a few guests experienced organizational issues. Crowds and atmosphere are mostly positive, but some mention the ship skews older and can be noisy. Internet connectivity is a common complaint, with slow speeds and outages. Specialty services like spa and kids' programs are praised, but accessibility and upselling are noted as areas for improvement.