This was our 4th cruise in 2 years with our children, and 3rd with Carnival. (Fantasy, '04, Victory, '05).
We were originally scheduled to sail again on a 3 day cruise on the Fantasy, but it was switched in April to the Sensation. It bothered me a little knowing that the ship was going through some refurbishments after being used in New Orleans for the evacuees, but after reading some comments, I was fine with the switch.
Since we had just returned from a Royal Caribbean 7 day Southern Caribbean cruise, the 3 day cruise seemed like it would go by very fast, but the pace of the ship and itinerary was great.