I cruise both lines, but my preferred is Princess. I am in my 50's and not a wild partier. I feel Princess is classy and refined. My last 3 cruises have been on Carnival for various reasons. Before the cruise I always tell myself to lower my expectations because it's not Princess. Then I go on the cruise and have a great time. On Carnival I feel like I'm in my 20's again and do things I don't normally do on Princess. One thing I love is when a crowd is gathered in the atrium and everyone is belting out 80's songs. (or some other genre) So after my last Carnival cruise I said to myself, "I don't have to lower my expectations. Carnival isn't inferior to Princess, it's just different". And I enjoy both types of cruises.