I'll probably make this short. My wife and I chose Princess because we wanted a Hawaiian cruise and RCCL did not have their scheduled when we decided to book it. That being said we really like Princess and would not hesitate in cruising with them again.
Embarkation was great. Got there between 11:00 and 11:30 and we were on board and in our cabin by 12:15. Although the luggage didn't arrive until after dinner.
The food was a little more exotic (i.e Buffalo) but was very good. Even the coffee was not too bad.