There are two main problems with the Chinese room experiment.
1. Thought experiments don't really prove things, only real experiments do.
2. John Searle ignored the person who created the room, who did most of the intellectual work, making the rest derivative and predictable.
It is the person who created the room who is the real intellect there, not the room itself or the person manipulating symbols inside the room. It is the room's creator who solved the general class of problem of language translation in a manner superior to the present entire output of humankind, and who therefore deserves the label "intelligent" more than the room itself.
It's as though I were having a discussing with Searle and I say, "You should read this book, it's intelligent." and he replies, "What's so intelligent about it? Ink? Glue? Dead tree matter? The book-binder or person who sold you the book, perhaps?" "No," I would reply, "when I say a book is intelligent, I mean it's author is intelligent, not the book itself!" Likewise, the creator of the Chinese room, were such a person to exist, would be more intelligent than the room itself, although the room itself would admittedly be impressive in its own right.
The room would not need to display "understanding", because that need would have been eliminated by its creator, who somehow reduced the problem of general understanding to one of rote mechanization.