Overall, the Royal Princess & the Baltic Cruise were great! The ship is extremely nice, well laid out (with a few shortcomings) and the crew was very focused on making the passengers happy.
First the downside: The lack of a promenade on the Royal is a major issues for those of us that like to walk on the deck. The Princess "answer" is to walk on the running track on the Sports Deck; that is a "non-starter" for the casual walker. They need a traffic cop to keep the lanes straight for the runners, walkers, picture takers & bored teens.
The lack of central staircase is another major issue for ease of movement on the boat. Elevators are crowed & those wishing to walk are pushed to the front or rear of the boat to access stairs. This was a major issue on the day of departure from Copenhagen after the lifeboat drill.
We found the cabin to be comfortable for two people with room to entertain another couple before dinner. Cabin was very quiet & we did not hear our neighbors. Balcony was too small for this class of cabin.