I actually did back-to-back cruises beginning Oct 19.
I wasn't impressed with the embarkation process. Got there early and the lines were very long. Going thru the security process went easy enough, no problems there. Then came the actual check-in process; I have cruised with NCL over 20 times and each time I have checked in there have check-in lines determined by the extent of loyalty to NCL. Obviously the greater your loyalty to the company the shorter you line was. At Tampa there were three lines. The shortest was for those who had paid the highest fare, suites, and penthouses. I have no problems with that. The problem comes with the other two lines; there was no difference between them. The first time cruiser and the platinum cruisers were all herded together. It made the first impression appear as though my loyalty to NCL doesn't mater any more. It made me feel disrespected.
When it came to actual boarding I became confused. Usually boarding begins around 11:30 even tough you are usually told it will happen at 12:00. Our boarding began a little after 12:00. What was confusing was the fact that the ship had arrived a day early due to mechanical problems so most people expected the ship to be ready for early boarding. There was never any explanation given as to the delay in boarding even though several ask for one. In the past we have always been told boarding couldn't begin until everyone from the previous cruise had cleared customs, however, in this case everyone had cleared the previous day.
4512 was the better of the two cabins. Although they were both on the same deck and both had portholes, and both on the starboard side and basically the same. Cabin 4512 was just off of the forward elevators and was about three feet longer. That extra three feet made it much easier to get around the beds which we had placed together to make a king. Cabin 4620 was mid-ship just off of the mid set of elevators. Many people are concerned about possible noise on deck four but we heard very little.