Big Apple, quick question...
In that "before" shot of the Chrystler Building, I see open parcels (open as in, no development, but apparently "no ground" either) in the vicinity of Grand Central. Are those cut-and-cover subway tunnels? If they are, holy heck!
More on-topic, I didn't see one yet for NY Penn Station and Madison Square Garden. It's probably not even worth it to mention. I'm sure our opinions will be close to 100 percent agreement.
One for Pittsburgh:
Former convention center to the behemoth of one they have now -- BETTER!!!!
Sorry, I do not possess any pics of either one.