Welcome to our cruise mad family
I have only done 2 NCL cruises so far, one on Jewel and one on Crown....I will be aboard Gem later this year on a shakedown cruise.
Freestyle ships, in a nutshell, give you larger choice of places to eat, complete freedom as to what time to eat and what to wear. They also offer good levels of activities during the daytime and evenings too. The freestyle way is not to everyone's taste, but if you are looking for the less formalised cruise, then it is ideal. Age groups are wide, you will get some children (obviously dependant on the time of year/schools etc) and the ship will cater to most if not all levels of how active or not that you want to be while cruising.
As to your chosen itinerary, I cannot comment as have not done the MR cruises as yet
All in all, you should have a very pleasant cruise.
