I think the outside is so bad because they've made it open to the sky and that restricts where they can put climbing equipment. I'm sure the Orangs care less about seeing the sky than being able to make much more use of the area available to them. So much of the outside is just space they cannot use...
I like the height and the enrichment at Chester a far cry from the old house with what looked like large children climbing frames.And the outside enclosures are really good.