We quickly tired of the constant badgering to buy drinks, merchandise, etc. You have to walk through the spa (more selling) to get to the gym. Through the casino or gift shops to get to most anywhere.
For dinner there was a minimum 30 minute wait for a party of four at Taste and the Manhatten Room; yes we tried a different time every night. We felt that this was designed to get us to make reservations at a specialty restaurant. Yes we received drink vouchers, frankly we were ready for dinner and just wanted to be seated. Plus we could not count on dinner timing vs. show times.
Larger parties had reservations and waltzed right in to Taste and Manhatten at their appointed time while we waited. Service was efficient, impersonal and brisk. Dinner one night took over 40 minutes to arrive. Restaurants were very noisy with service noise. When we went to the buffet for dinner, it was quite limited. Did not appreciate this manipulation at all.
Gym equipment was very poorly maintained -- one day I used five different cardio machines and the touch screens were not working on any of them. Husband had a similar experience. The batteries were dead on one of the two rowing machines. The staff person I approached about it was indifferent, and batteries (4 AA's) were not replaced for the duration of the cruise. I almost did it myself. Cardio equipment is in need of a total maintenance overhaul.
Usually on cruises we meet other adults and socialize with them. Not this one -- we raraly saw the same person twice. Atmosphere was like an airport or bus terminal -- keep to yourself and carry on.
Positives? Predictably pool deck was a zoo but there are places to go (Upstairs forward, Spice H2O) to get away from crowds. Passengers (adults with small children) who ignored the "over 18" at Spice were approached by security and asked to leave. We went to several shows on standby and got in. Embarkation/disembarkation was great. we liked the inside stateroom configuration and storage options. Outside rooms with the wave looked awkward.
Our kids (14.5 and 17) did not find other kids to hang with -- their problem, not NCL's. Unanticipated dynamic for a 17 year, 10 month old: 18 year olds may drink on this cruise if parents sign a waiver. So daughter's peer group was drinking, she was not, and she did not like hanging out with "tipsy" 18 yo's.
We think Epic is good for large family groups, people who want to spend the extra $$$ on Haven and specialty restaurants, and people with elementary and middle school age kids. We won't be back.