We purchased the 4-park pass and others who do so should be aware that the parks are not co-located. Rainforest Station and the Butterfly Sanctuary are close together in Kuranda while the Wildlife Habitat is about an hour north of Cairns and the wildlife dome is on top of the Reef Casino in downtown Cairns. That said, all the parks were clean and the critters appeared to be well cared for.
The aborigine exhibitions and duck boat ride at Rainforest Station were well worth the price.
At the butterfly sanctuary, the butterflies were quite beautiful, swirling around visitors in swarms and readily landing on bright clothing. There's a little café next door that serves an excellent aussie burger.
The wildlife habitat was fairly large - My wife and I spent 4 or 5 hours there.
Awesome opportunity to see loads of beautiful butterflies in a natural habitat, as well as seeing larvae and learning cool stuff. Unlimited great photos!