Our kids LOVED Legoland. It was also a very slow day there. Not very many people. We don't have any Legoland anywhere near us, so for us, it was a must see. There wasn't a lot of shade, which can become a problem. Our wish child just melts in the heat so we had to quickly change courses. All rides we were able to walk on. I will agree with PP, not the greatest for mobility. We had to back track a few times with our strollers as some places had stairs and weren't marked. We also did not do everything.
So, if you are very much into Disney/Universal, I am not sure it would be worth it. But we did not do Disney or Universal. We did Animal Kingdom and Sea World. The lack of special treatment didn't bother us. But if you go to the other places, I can see why it would be a bother.
Kennedy Space Center....we thought about that but thought, with our age range of kids, it wouldn't be a good idea. So no help there