Out of the 22 cruises I have been on only one is a transatlantic. In November of 2017 I took my 22 yo son on the Celebrity Silhouette. It was the trip of a life time! We booked the trip 10 days before it set sail from Rome. The folks on the Celebrity customer service were great at making this trip pain free. The trip included stops at Florence, Barcelona, Majorca, Canary Islands and stop in France that was cancelled because of the weather. My son was the youngest passenger. This didn't affect him till we actually had 7 days at sea. Our cabin was a balcony mid ship on the 8th floor. We had the late dinner seating because of how late we booked the cruise. The port days were awesome. The sites were not that busy because it was near the end of the tourist season. On sea days they had guest speakers that I found very interesting and I also took origami classes. There was also games and tournaments during the sea days. I joined my first slots tournament. The pool was busy but the water was too cold for a Floridian. Just realize the days are easy its the 7 sea days in a row that are a little trying if you don't decide to be adventurous. I tried a new thing every day and went to every free activity I could. On my down time I read a book and did my Sudoku. I'm not a fan of NCL and HAL is a little too quiet for me. Have you sailed with either of them? I would gauge your experiences with the 2 cruise lines with your activity level. We usually cruise RCL so we are used to tons of things to do but I knew going into this cruise it was not as high energy as we were used to so I came prepared.