I went to Ontario Place in late August just to get some fresh air so very little expectations of theme-park activity will be used as comparison here. The fact that it was FREE entrance didn't hurt one bit. Little did I realize that with minimal expectations attitude it turned out to be a very enjoyable day in the park.
If we had the same weather year-round as Vancouver and that Ontario Place had more greenery/forest, I would have taken it as Stanley Park by mistake. The docks with the boats, nice walking pathway not quite bicycle/inline skates friendly, the spectacular waterfront view on a blue sky white cloud day with the water shimmering.
I did block out the whole Ontario Place experience to see the comparison with Stanley Park but the shows, rides,attractions, waterparks did put smiles on faces of Families with small Children. With the families came screaming Children, crying Children, running Children, etc...
Normally, in past Summers it would cost for Grounds Admission then a purchase of either the All-Day-Pass or Pay-as-you-Play. This Summer I'm glad it was free entrance so I could casually pace around soaking in the warm Sun and intake the beautiful lakeside calm peaceful scenery.