They are pretty good. Not outstanding, but not bad either - certainly better than old fashioned grottoes. I like the fact that you can see at ground level and that all three (lion,tiger,jaguar) have a mix of glass viewing and mesh or harpwire viewing. The black jaguars (my favorite animals at our zoo) have the worst of the three exhibits because they have worn down the foliage over the years and it is looking a bit barren.
Funny you should ask this now, because yesterday I was at the zoo and docents got an inside tour of the tiger exhibit which is currently being modified. A steel mesh fence (which is dark and should be good for photographing through) is being put up on one end where the harp wire was. This will include a training wall for keepers to interact in front of the public as well as a tug-of-war feature for tiger and guests. A similar mesh wall (with a door that can be opened or closed) will divide the current exhibit in two. I have mixed feelings about this as I hate to see that very nice exhibit made smaller. The reason for this is we are currently introducing our male to a newly arrived female off-exhibit and want to be prepared for cubs. This way the male can be out on one side and mother and cubs on the other side.
My biggest complaint about cats at our zoo is we have no small cats (and believe me, senior staff know very well how badly I want to bring small cats to our zoo).