Sadly its the second year in a row where an NCL - Sixthman cruise ended with an epic failure. Both years hundreds of people bought airport transfers and both years the buses did not arrive for the hundreds of people who waited outside for nearly 3 hours after disembarking the ship. Many had to take cabs, Ubers etc to avoid missing flights.
Sixthman takes no responsibility for the failure, blaming NCL. But it's important to know that this company is OWNED by NCL since 2012. When a company refuses to advocate on behalf of their bookings, there's something wrong and they should be avoided. It should also be noted that two people posted comments about the transportation failure and Sixthman opted to take them down from their FB pages, claiming that it has nothing to do with them in spite of their NCL connection.
Clearly, you're only going to get to see the positive things they want you to see and that too should cause you to worry when they don't want you to see the problems their cruisers encountered.