First, let me make it clear that the NCL Epic is a very nice ship and that we enjoyed the cruise. That being said, I had a few issues with it's design.
We were in a standard balcony room. This one had an oversized balcony which was very enjoyable as our adult son, who was in a Studio cabin would visit us often and there was ample room on the balcony for all. The room itself was efficiently planned with a good amount of storage space. Enough has been said about the bathroom, or lack of a bathroom, design in other posts. We found it OK overall. Just wish the door to the Toilet opened as much as the door to the shower did. This could be an issue to larger guests. We both agreed that the sink is not practical. It's a bit small and no matter how careful you are water will splatter. The couch is not comfortable at all and in a spot that doesn't let you watch the TV, which could be solved if the TV could pivot a bit. It doesn't. Overall form won over function. The room is pleasant enough but could have been better with just a few changes.
The ship was clean, crew pleasant, food good. All the basic requirements for a pleasant cruise. We saw most of the shows and enjoyed them all. This is a great ship if you like shipboard entertainment. Blue Man Group can be a bit loud so be warned if you are noise sensitive. I suggest that you go and wear concert ear plugs. The Epic theater is not as impressive as theater on other ships at first, but it does have good points. The seats are comfortable with ample leg room. The theater which is surprisingly small for a ship this size has unobstructed good views from all seats.
Deck 6 has the casino and you find yourself walking through it often. Areas can get smoky. I noticed many Orick portable air cleaners placed in narrower areas to help this problem. Obviously they know there is an issue and are trying to fix it. We are non-smokers and this was the only area that there is a noticeable problem.
One feature that we missed was the ability to walk outside around the entire ship. Because of the Spa Suites the front quarter of the ship is blocked off on top. There is little open space on this ship. The decks that are open are full of lounge chairs and the pools. Even the jogging track is on one side of a deck and just loops around at each end with a beautiful view of the lifeboats.
I also wondered why lemonade is not offered as a free beverage as it is on Carnival and RCCL. This was our first time on NCL. Freestyle dining was nice but we did miss the rapport you get by having the same wait staff every night. We did My Time dining on The Oasis last year which is similar and asked for the same waiters which was nice.
Overall the Epic is a nice ship with a lot of elements that could have been put together in a better manner.
I like taking pictures in 3D and was hard pressed to find adequate subject matter. Last year on the Oasis, I was snapping photos all over the ship. To summarize, the Epic is like the Oasis without the WOW factor.