We just returned from a family trip with our two kids (ages 10 and 12) on the Liberty. Here are my comments:
Pre-embarkation: We had arrived in Florida a few days early. Car rental return for Avis at the Hyatt Pier 66 went smoothly, and they rushed the returns process so that we wouldn't miss the shuttle to the port.
Embarkation: Just as chaotic as others have noted. Pulling up to the terminal at around 11:30 am we got stuck in bumper to bumper traffic a few hundred yards back. The porters seemed overwhelmed by the number of people arriving. Once we got in line for security, after about 10 minutes we were told to get into another line for families, which moved very quickly (by contrast, my parents, who arrived about a half hour behind us, were in the security line for about an hour and a half). Once through security, we were directed into a very long check-in line. My son noticed that there was a separate check-in for C&A Gold members, something that the RCCL employee did not point out notwithstanding that our confirmation noted our status. Within 15 minutes we were on the ship.