I would have to say the main reason we cruise Carnival over Royal is price. Even for the Royal ships that don't have all the bells and whistles that the newer ones do the price for the same # of days and ports they usually cost more than Carnival. And price is the biggest reason we choose one cruise over another. We have cruised once on Royal and I really did not see any difference in quality of cabins/ food or the way the crew is. One difference we have seen in the dining rooms is that on all of our Carnival cruises the Maitre'D came by the table every night, even the one time we did the your time dining and for the one Royal cruise we had absolutely no idea who the Maitre'D was, yet Royal expects you to tip him and he is not in the tipping pool on Carnival.
Caribbean Trip Reports
Star Princess 2005, Sun Princess 2005
Caribbean Princess 2006, MSC Lirica 2006 , NCL Pearl 2007, Majesty of the Seas 2008, Carnival Destiny 2008, MSC Lirica 2009, Carnival Valor 2009,Carnival Legend 2010, Carnival Liberty 2010,Carnival Fantsay 2011,Carnival Valor Feb 2012, MSC Poesia Dec 2012, MSC Poesia April 2013, Carnival Legend Nov 2013, MSC DIVINA Jan 2014, MSC Divina Oct 2014