Just back from a 7 day cruise aboard the Royal Princess departing from Barcelona and ending in Rome. This was our first time on a Princess ship. Previously, we have sailed on RC and Disney. We were traveling with our 15 yr old son so I will add some color on the teen experience.
Overall, we enjoyed our time on the ship. We would gladly do another Princess cruise though there was nothing that would entice us to only cruise Princess. The ship, food, entertainment, etc were on par with the other cruise lines we have sailed with.
The ship itself was very nice though you can see some aging in carpets, rust etc, Nothing that would deter us from sailing on the ship but some cosmetic touch-ups are probably necessary.