The city tour was excellent, as was the transport to and from to the NASA space center. The price paid was reasonable as well.
However, this was in December, and the crowds at the space center was huge. We had to wait for a long time to get in to the space center, and the wait for the tram tour was about 45 minutes or more. Although this cannot be controlled by the tour organizers, they could offer the option of the space center tour on its own without the city tour, and drop off people at the space center at 9 AM when it opens for visitors. By doing so, it would be faster getting in, and people would have the entire day until 5 PM to tour the space center. I understand this option may not be the best for everyone, but, I am sure there would be sufficient people who are really interested in spending an entire day at the space center.
It was nearly 1.00 PM when we got in to the space center, and we were told to be at the entrance to go back to downtown by 4.45 PM, thereby giving us less than 4 hours at the space center. Given the crowds, this time period was not at all sufficient to see and experience even 50% of what they had to offer. As a result, I came back the next day on my own, so that I had the opportunity of experiencing more of what they had to offer.