I love zoos and this zoo too. I spent an afternoon here with the kids and we had a great time. The outdoor enclosures/habitats aren't the naturalistic ones with hidden barriers or open moats that are required (in my opinion) for a zoo to be considered top tier. The buildings are well designed and indoor habitats are quite nice.
The prehistoric park was a bit weird as I come to zoos to see real animals, but still a pretty cool bonus attraction. We didn't have time to visit the conservatory as well, but it looks like another bonus attraction with many diverse plants and in the warmer months, filled with butterflies.
I've been to zoo's all over the world including Toronto, San Diego, and London Zoo's. While the Calgary Zoo doesn't measure up to the best zoos in the world, I'd be happy to visit this zoo every time I'm in Calgary.