The Lied Jungle's collection has gone down but its standard of exhibitry has gone up, since the worst of the exhibits have either been removed or renovated over the last several years. Just about the only left that I really think can be called bad is maybe the tapir exhibit.
I actually feel that the two tapir exhibits got significantly better since both now allow the tapirs access to the upper portions of the exhibits and natural foliage. They essentially doubled the size of the exhibits instantly.