Mainly the cleanliness of the place along with the enthusiasm of the staff. There is a variety of rides for all tastes and if one gets fed up with that, then just a break to walk round the park.
I was there with a Coaster Club and due to their exclusive session, and other members having done it enough, I managed Leviathon six times solo before the GP came in. The whole park is a delight.
I don't have the knowledge that Ben does, but the park is served by public transport from Toronto.
There are several things to do around as well described by Ben, but for the aviation enthusiast there is a great aircraft collection at Hamilton which includes the worlds only other airworthy Lancaster.