We did 11 nights on the Royal Princess in 2018 and then 14 nights on the Sky in 2020. They are definitely different even though they are in the same "class" of ships. The Sky was the first Princess ship that was actually BUILT with and for the Ocean Medallion rather than retrofitted. This meant that the internet connections were, in my opinion, much more integrated and reliable. The Sky had a much more open feel to it than did the Royal. I spent a lot of time on both cruises in Princess Live!, so I can comment that there is a major difference between the ships in that regard. With COVID, etc. I will double down on my preference for the Sky's Princess Live set up as it is an open area with lots of natural light. The seating was also better, in my opinion. The restaurants and the specialty restaurants seemed similar. With the Sky suites, the public areas on the upper decks were somewhat reduced, but not in a noticeable fashion. The ships are more similar than different, but the little differences came out in favor of the Sky in my opinion.