KSC was not worth my money to see. It was $32 or so. Unbeknownst to me at first, the price drops significantly in the afternoon (to something like $18) when the last tour bus leaves. This was noted only on a small signboard on the ground, separate from the main price list at the ticket window. I was interested only in the visitors center because I had read from a trip report that post-9/11 the bus tour stays a mile or so away from the attractions (like launch pads and shuttle refurb facilities). Also the bus tour takes 2+ hours and I didnt want to be stuck if it wasnt good. If the bus tour is running, you must pay for it whether or not you do it.
In any case, the 3D IMAX movie of the international space station was excellent and the saving grace for the visit. There was another 2D IMAX movie playing as well. The space shuttle disappointedI thought it would be a close facsimile, maybe even a backup. It was a fabric mockup, not worth any wait to enter the cockpit. Kids would probably still like it. The café was horriblegas-station quality food.
As for the rest of the visitors center, the flight museum in my town has similar exhibits for a much lower price. Had the KSC been $10-$15 I would have felt it was a decent deal, if only for the IMAX movies, but not worth the drive from Orlando for the KSC alone.