My wife and I are in our late 20's. This was our 4th cruise, 1st with RC. We previously sailed with Carnival and Norwegian. We did not sail with any other group, family, or friends. It was just the two of us.
I will give the nod to RC on the Beauty of their ships. I was blown away by the structure of the Liberty of the Seas, and what it all had to offer. Overall the food was very good; I can't believe other reviews in which ppl seriously complain about the food. We found that the food on Carnival and NCL was also very good, and very comparable to RC (at least we didn't notice a difference).
Overall service was very good, just as we experienced on Carnival and NCL. At times I felt like the bars were a bit understaffed. I had an unlimited soda package, and sometimes it took a very long time to get a soda.