This was my third NCL cruise in as many years, on the third class of ship - Epic being by far the biggest of the three (Jade and Star being the other two)....and that, frankly, was the key issue - and this was a concern amongst MANY of my fellow NCL passengers cruising on Epic for the first time.
The 'smaller' ships (if a 2000+ pax ship can be called small) all have the excellent NCL range of speciality restaurants....Epic was no different in range, however the restaurants were not scaled-up sufficiently for a 4100 pax ship; as a result the restaurants were booked days in advance. Similarly, the a la carte complimentary dining rooms (Taste & Manhattan) were very good, but there was regularly an hour's wait for a table - this is OK when you have planned for it and have the time to while away in the bar, but not good if you are aiming to get to one of the evening shows.
The enduring memory from the ship is that it is configured not for families (ie kids) but rather for revenue generation....for example:, an entire deck of this monster vessel was dedicated to the casino and the key selling points (ie the ice bar, circus etc) were all at additional cost. The other key points, such as the HUGE aft screen, were totally underutilised and only served to provide the world's biggest parasol for the suntan deck!
As per every NCL ship - standard inside double cabin. Clean, good facilities and well looked after by the excellent staff, towel animals included!