I dove Nassau with Stuart Cove off of the Sovereign of the Seas (Royal Carribean) a few years ago and had a blast. We hit the port early (an entire day early in fact due to a storm at our scheduled stop of Cococay), got priority treatment to disembark early, took the trip across the island (long ride), two great dives, and I was still back in time to spend dinner with the group at Carlos 'n Charlies. Overall a great experience and though it was busy I didn't feel like cattle one bit.