We just went to KSC over Thanksgiving (left our Disney vacation to do so). This was my 6th trip to Orlando and I am sorry I didn't go sooner. It was really interesting. I was concerned, because I read some "not so great" reviews on trip advisor, but it was extremely interesting and I am not a space nut.
One word of advice - Leave Orlando EARLY! It took us over a hour to drive there. We didn't have a map, so I'm sure we did not go the most direct route. Still, I am certain we did not drive that far out of our way. If you get there early, you will have less congestion in the lines to get in.
I bought vouchers from
AAA, but we still had to stand in a 1/2 hour line with people with all different types of reservations. It was incredibly disorganized and I think they really need to do a better job of getting people in there (this was at 10:40 am). There is also a smaller wait to have your bag searched. You can't take any type of food or beverage in there.
Once we were in, we watched both IMAX films. They were excellent and the one about the space station gave me a whole new appreciation for the space program. Films are 1hr 15minutes total between the two. They are in different theaters at different times.
We only got through 2/3rds of the bus tour before we had to leave to return to a 6pm ADR (which we were very late for). So - if you have an ADR at Disney that night, make it later.
The bus tour was interesting. The saturn rocket was interesting. We saw the shuttle on the launch pad. We missed the Astronauts Hall of Fame and several other attractions because of lack of time. They did allow people to come back a second day if they had their ticket validated. But you had to return the NEXT day.
By the time you visit, they will have some type of shuttle simulator ride completed. I suspect it will be similar in principle to Mission Space.
It was a great day. My only regret was that I did not allow enough time for my visit. But do keep in mind that I was there the Friday after Thansgiving so I am sure it was maximum crowds. Still, the only annoying line was to get in. Oh yeah - the lines in the gift shop were 20 -30 deep. Visit early!