We selected this sailing for TWO reasons - It was NCL (we previously went on the Prima and Encore), and the itinerary included the Seychelles, Cape Town, and Dubai. The 18 days were not a problem; we've been on longer.
What was not thought about:
THEATER ENTERTAINMENT - I was surprised that on an 18-day cruise, one gets the same amount of "Broadway Style Productions" as on a 7-day cruise, TWO! One production show was on day two, I think, and their wasn't another major production until day 16 and 17 of the cruise. The remaining days were filled with a 45-minute show of a violinist, a comedian, a musician (we had to watch him again for Elements), and a barber quartet. I felt that at least a minimum of one major production should have taken place each week, i.e. Kinky Boots, Choir of Man, Donna Summers, or some new production or cultural entertainment based on the destinations could have been brought on board.