I usually check the cruise air price but have ended up booking my own air. Deviations for flying in a day or two early add up. The only time we booked cruise air was to San Juan and we booked on a somewhat short time frame so cruise air was cheaper and the free transfers were handy.
A Bad Day At Sea [with power] Always Beats A Good Day At Work
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, 2014, Caribbean 2013, Coral 2014