I am in complete agreement that Miami is one of the best zoos in the country, and it is currently my third favorite zoo I've visited. Despite being being rated so high by many, I feel as if it doesn't get nearly as much praise as it deserves. Its ungulate collection is unmatched by any other zoo that isn't the San Diego Zoo Safari Park, there are both species of elephant, my all time favorite zoo aviary in Wins of Asia, and overall extremely impressive collection of mammals, herps and birds. Combine that with its lack of any very poor exhibits, and you have easily one of the best zoos in North America.
Some superb news! The pygmy hippo enclosure(s) was perhaps one of the only major blemishes on the zoo. I am ecstatic to hear that a new one is being built. With that taken care of, the only major issues with the zoo are probably the ape enclosures (a good size, but is way too open) and that secluded little concrete pen for cassowaries. After these are dealt with, Miami won't have a single bad enclosure in the whole zoo!
Quickly reflecting, Zoo Miami would rank after Bronx, SD, SD Safari Park, and the NC Zoo for me. Yet it would come just before Denver. It deserves the praise, yet I fully understand how the zoo can come off as slightly boring, due to the same exhibit style. This is changing though, Amazon and Beyond (an amazing complex, although I couldn’t see 1/3 of it) and the Everglades exhibit (very good, just needs to grow in more) both represent a bright future for the zoo. Wings of Asia was amazing, wish I could have spent more time there, thankfully though I will be in the Miami area pretty regularly from now on.
Collection wise Zoo Miami is an assembly of basically every animal that is on my favorites list. Elephants, okapi, banteng, gaur (spent 20 something minutes with them), nyala, dhole, rhim gazelle, babirusa, malayan tapir, and southeast asian birds. The hoofstock collection is great, only rivaled by both San Diego Safari Park and the Bronx Zoo probably.
I personally found the chimpanzee exhibit to be fine, as did I the orangutan exhibit. Both had some nice vegetation and were fairly large. The gorilla exhibit was more open though and could have definitely just been another hoofstock exhibit. I wouldn’t be opposed to the zoo updating these exhibits, as they are fairly weak points. I did miss the cassowary exhibit though on my visit, guess its not the easiest to find.