I have cruised to Hawaii and have also been there on a land vacation. I enjoyed both experiences, and Hawaii is one of my favorite destinations.
I preffered the land vacation because there was not enough time on the Islands during the cruise.
Carnival Liberty New Year's Eve 2007
Liberty of the Seas 5/2008+11/2009
Allure 1/16/ 2011
Independence of the Seas 12/29/2013 Top-notch!