Probably one of if not the best things out of Ragunan. Most of the exhibits are just wonderful (Especially the main gorilla exhibit and the massive Bornean orangutan exhibit).
Demolishing the primate complexes in the main zoo and moving them in the Schmutzer is one of my biggest wish, considering some species are only present outside of the primate centre (I.e Natuna Islands surili, Gorontalo macaque, etc.)
The Primate Center is like a completely different zoo compared to the rest of Ragunan. It's a two-hour adventure to see almost 20 primate species in very good exhibits. The Gorilla and Orangutan complexes are amongst the best in the world.