How about extended comparisons between different lines and different ships within lines..
More thoughts; ports of call, independent touring, emergency situations - what the crew is doing that you do't see, the real story behind "recommende shopping"
All I ask is a tall ship and a star to steer her by; John Masefield
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, 2014, Caribbean 2013, Coral 2014, Regal 2014
Star Clippers: Royal Clipper 2015