First of all, let me give a disclaimer. There are up to 3,000 people on each cruise. Each person is going to have a different experience from the next. Your experience also depends on your level of expectation. This also varies from person to person. Read these reviews and do your best to create the experience YOU want. The possibilities to do so are endless on a trip like this.
That being said, I would like to share the experience of my husband and I, and to tell you up front that we had no real expectations as we had never cruised with NCL nor been to Europe.
We'll start from embarkation: absolutely a breeze! No lines, no issues. Cabins were ready when they said they would be and luggage was delivered promptly thereafter. (Cabin was awesome, beds were like a Westin Heavenly Bed, very comfortable!).