Just prior to the cruise date we were sent an email stating the "staggered" check in times that Celebrity would like you to use. I say disregard them as their shore side staff are excellent and checking in/boarding was the smoothest I've seen in ages. Each Captains Club category had its own line and this helped immensely.
We were welcomed aboard with champagne and there is a "specialty dining" booking table set up just after you enter the lobby. If you are going to use this feature, I'd recommend booking it right away as they fill up fast with the most preferable timings. That said, if you wait you can always book later in the trip as many tables had cancelled and were empty during our dining periods which were between 7-8 pm (complimentary to late seating).
Many cruise critic members had problems signing up for the "Cruise Critic Social", so we arranged to meet at the deck 15 bar for the sail away to "meet and greet" and watch the Miami skyline disappear behind us. The problem was resolved when a member took it upon herself to collect all the names and submitted them to the service desk onboard and everything went nicely during our official "Meet and Greet.
We had the last balcony, port aft. It's larger than most and very private and quiet. Funny how most people want amidships and the "bump out".