Overall, this cruise was excellent, and I would highly recommend it to others. We were traveling with a group of 45 people, and so flew together and stayed in Copenhagen prior to embarkation at the Hotel Copenhagen Island.
The Hotel Copenhagen Island was fine. It was a bit of a walk to the central area, but not too bad, maybe 1.5 miles. They did have a wonderful breakfast buffet.
This was my first cruise, so I cannot compare the Emerald Princess to other cruiselines.
Emerald Princess: A310. Very well laid out. Plenty of space for two of us to hang clothes, put clothes in drawers, and store our suitcases out of the way. Bathroom had plenty of space for our stuff. Balcony was smaller than some of my fellow travelers had previously (no lounge chairs would fit, but two sitting chairs and a table, which was fine for us).
We did not experience hallway noise or any other issues of noise.
Because we were on the A-deck, we had great views from our balcony - I had no problems with our room.