I've been on 2 other Norwegian cruises that were great, but the Epic is awful. The inside cabin was very nice, but that's where it ends. The food is not good and lacks flavor, but here is the worst.
To get to one of the 2 main dining rooms (Taste) from our mid-ship aft. cabin we had to walk through a smoke filled casino as the elevator did not stop at that deck. Next the Atrium lounge where they had entertainment did not have anywhere near enough seats for a 4,000 passenger ship.
They had oversized chairs too large for one person, but not large enough for two with huge spaces in between that they could have put in many more single seats. The large round tables also took up a lot of space where they could have put in seats. People had to sit on folding chairs to view game shows, music etc. The same was also true at the Bliss lounge, not enough seats, but room for two sofa beds where they could have fit at least 30 more single chairs. The dance floor at the Bliss lounge was so dull you could not dance on it.
My mid-ship cabin near the aft elevator was great except we had to go through a smoked filled casino to the "Taste" main dining room, as the elevator did not stop at that deck.