Robert, guess I am not going to be much help on that one - all of our past cruise and our next one on the Conquest, have been Carnival.  I have never gone on Princess, although I do believe they are owned by Carnival now.  We started with carnival because the kids were teenagers and traveled with us back then and we always liked the way we were treated onboard Carnival so never switched.  Plus, our travel agent always told us that the best deals to be had were aboard their ships.  I know Zebra is a frequent Princess guest so when she comes back, she may be able to give you some insight....