This was our fifth cruise, and we have sailed with Carnival, Norwegian, Princess and this was our first Celebrity.
Pros.
Dining room service. The main and assistant waiter have only a few tables to supervise, so they have plenty of time for each table and they do an excellent job. Our sommelier Stephan was fantastic and very knowledgeable. Once he knew what we like he did a great job with new recommendations, and even warned us against some of our choices (and he was always correct).