I've haven't been to the Science Centre since the early 1990s. I do seem to recall, however, this place had more "stuff". There were a lot more hands on exhibits, more stuff to play with. They seem to have gutted the halls. What's left seems to make little sense and is full of fluff or simply scientifically incorrect. Consider:
http://www.ontariosciencecentre.ca/tour/default.asp?exhibitionid=11
The science centre claims the human genome has 100,000 genes? It's under 30,000 according to the human genome project. The 100K estimate is a decade old before the results of the human genome project.
This place is still crack for kids, however.