I believe both lines are ver comparable. The only HA ship I have sailed is the Zuiderdam (2x's). I have sailed RCCL ships four times. I am most comfortable with these two cruise lines. From what I have read regarding the other HA ships, I believe the Vista Class ships are different from the other HA ships and are more like RCCL Ships. I do apprectiate your comments regarding the Vision class ships as I beleive it will either be this ship or the Oosterdam when all is said and done. In the meantime, have you sailed the AOS? Tht is our next cruise in February.