Just watched it. A very well done documentary. I knew that the monstrosity that is Madison Square Garden replaced it up top and that Penn Station was relegated to a subterranean place where you didn't feel comfortable awaiting your train. Certainly not the grandeur that once welcomed visitors to New York.
With some very good luck, however, there could be a happy ending to the Penn Station story. There are plans by the State of New York to open the neighboring U.S. Post Office building, which is now owned by the state and sits largely vacant, as the replacement for the current Penn Station. The benefits would include architecture that evoke memories of the original structure of Penn Station. The U.S. Post Office building was only built a few years later and designed by the same architects.
DFF