I actually don't mind these exhibits, because even though they are smaller than the other great ape habitats at Apenheul, at least the orangs are off the ground and brachiating like they do in the wild.
I still think they are SURPRISINGLY small, especially in comparison with the obviously great other exhibits at this zoo. Like... what if two individuals gets into a fight and want to get out of each other´s sight?
Then I suppose they will climb upwards or escape to another island. I might be more worried about this if we were discussing chimpanzees. Orangutans are very mild-tempered.
Toddy, you are right. The recent presentation of this exhibit at Zoolex shows that the apes have access to the different islands, as well as the indoor space, all at the same time. So my worries were unfounded and I am now convinced that this is a great exhibit, indeed! Very nice.