We didn't go with a Carnival tour, because we drove into Canaveral for 8/31/08 cruise. We did stop again at KSC after our cruise and really enjoyed it. If you don't get down to that area often, it is a must see.
If you go, spend about $20 and get your picture made in the photo center. You put several people in the picture and they pose each of you as if you are floating around in an anti-gravity atmosphere. We loved the picture we did last week.
We also did the simulator and it was great.
Been there - done that:
2005 Holiday, Sensation, Conquest,
2006 Conquest, Celebration, Holiday,
2007 Freedom Grand Med, Holiday
2008 Fantasy & Sensation,
2009 Fantasy, Holiday & Dream Grand Med
2010 Fantasy and B2B Elation
2011 Monarch of the Seas
2012 Booked - Breeze from Barcelona 12 days