There's a difference between saying the entire exhibit complexes are appalling to a sizable group and saying individual exhibits in the complex are appalling. You won't get much argument on the latter, but I still really like the Lied Jungle and Desert Dome despite a couple issues in each. It certainly creates an interesting dilemma when assessing the exhibits.
I think that we need to look at the Omaha exhibits from 2 perspectives: the human experience and the animal experience of the species that spend their lives in these buildings.
From the human experience perspective there are some dazzling elements of the Lied Jungle, the Desert Dome, and the Night Kingdom: waterfalls, dirt trails winding through rain forest foliage, shifting sand dunes, desert river, bat caves, and a whirlpool. There are design elements here that are Disneyland level quality. They are impressive and they are worth seeing.
Unfortunately the vast majority of animal exhibits within these buildings were built seemingly with 1950s animal care standards in terms of space and enrichment rather than late 20th century/21st century standards. Most of the animal spaces are tiny, sterile, concrete spaces. The hummingbird aviaries have been fatal for their residents because they were so small. The cat exhibits would never be acceptable in another modern zoo, ditto the tapir, aviaries, hyrax, wallaby, lemurs, etc.
The Omaha mega exhibits are good show business. They are appalling animal exhibits. To the great credit of the current management they apparently are trying to remedy the animal problems by putting more appropriate animals into spaces and removing the worst exhibits entirely (e.g., the barren raccoon island that exposed their residents to alligator predation!).
So my overall assessment of the Omaha Lied Jungle, the Desert Dome, and the Night Kingdom would be:
Human show business perspective: dazzling
Animal care perspective: epic fail
Overall assessment: No modern zoo exhibits, no matter how dazzling from a show business perspective, can be considered "world class" if they fail from an animal care perspective.
Omaha is not a world class zoo. It is a zoo with a great collection in some good exhibits and some really bad exhibits that have some dazzling qualities. I think that this would be a majority opinion in the animal care professional community, which is sometimes not the same as the zoo enthusiast community.
St. Louis has been steadily removing their deficiencies with the construction of exhibits that seem by consensus to be really good. In the past decade they have rebuilt half the zoo with their River's Edge complex, outdoor ape exhibits, penguin exhibit, invertebrate house, and apparently coming soon a new sea lion exhibit. St. Louis seems like it is a world-class zoo from both an animal care and exhibit perspective, and would be a good role model for Omaha to follow if they want to be truly great.