I have been on 4 cruises and the Gem was my favorite cruise to date. I enjoyed it much more than the Breakaway due to it being smaller, less congested, and much friendlier. It was easier to meet people and crew members. All of Norwegians' staff were polite, courteous, friendly, helpful, you name it!
I thought Dan Dan was a great Cruise Director and really gave his best performance in Cake Masters. That was so funny.
I plan on crusing with Norwegian again very soon and may try another ship for comparison.
Having been on the Breakaway in an inside cabin also on deck 5 I felt compelled to upgrade to a room with a window when I cruised this time on the Gem. It feels as if the Gem rooms are either larger or laid out differently and felt larger than those on the Breakaway.
I have been earning my cruises thru CAS so an inside cabin is standard and I personally do not feel the need to pay anymore that possibly a window upgrade. If NCL wants to throw in a suite or balcony for free I would not turn it down but do not think I would spend the extra on the room. I just do not spend any time there except to sleep etc.