We chose this ship because we like Norwegian, and the itinerary was appealing because we could tack in onto a stay in Barcelona.
However, the EPIC is a big ship, with all of the problems that come with jamming so many people on one platform. There is almost no deck space for anyone who needs quiet space on any deck where there isn't live entertainment going on. Inside, most spaces are very closed-in. Too many spaces are decorated in dark wood, which makes you feel a bit confined.
Getting around the ship is hard. Signage is deficient, especially signs pointing you forward or aft.