Hello! We took our family to the Kennedy Space Center in March of 2001. We did not buy tickets in advance, and the lines were very, very long (a Friday). One reason was that their computer was down and they were hand-writing credit card receipts. Luckily, we bypassed it when a traveler's check line opened. We almost missed the tour we wanted.
We did the deluxe tour, and were very glad we did! All the extras were well worth it. If you, however, want more time at exhibits rather than seeing facilities, the standard would be AOK.
Dh is a Boeing engineer, so this was a must see for him. I, a girlie-girl, was enthralled by this tour, it was one of my best memories of our first trip to Orlando. Ds then age 10 and dd age 6 loved it equally as well. They brought back gifts to their classrooms, and this was a hit.
Have a wonderful trip!!!
Barbara