A few thing to remember.
1) Carnaval is called the Party line for a reason. you will find many more drunks and younger people in the dining rooms with baseball caps turned sideways and wearing tank tops.
2) I recomend Princess for a youg family, great shows and kids programs.
3) Self serve laundry with irons.
4) Anytime dining with up to four restaurants to choose.
a) You can pick your table size and time to dine and receive special orders for vegetarian with added spices.
5) Cabins are generally larger on Princess, then those on Royal Caribbean.
6) The Plaza deck has the fewest cabins and a inside cabin will offer the best value.
If you want the names of Websites, with lowest pricing, let me know.