Sailed from new York to the Bahamas with my wife ans 3 1/2 yo daughter (and 13 friends). This was my third cruise, first on NCL. I enjoyed the free style atmosphere, and would rate NCL as my favorite cruise line.
Overall the Gem was nicely decorated and had plenty of room. I never felt crowded, even on sea days. The service was very good, no complaints, and the entire crew is very friendly. I took the "behind the scenes" tour, and would highly recommend it, for those who like that sort of thing.
While the pools did become somewhat crowed, there was always room to swim. My daughter loved the children's pool, but be warned. The pool is DEEP (5'9" all around) I could not stand up in the pool. This could be a potential problem. Also, the pool is very salty. A shower is necessary after each use. While the pool deck was also somewhat crowed, our group never had trouble finding a couple of deck chairs to share.
Mini Suite - Good size, plenty of storage space