Welcome to what it's like being in Philly all the time.
All of Amtrak’s trains stop in the same station in Philly, so a cross town self transfer is nothing like what it’s like being in Philly.
Exactly. To take the subway from GCT to NYP requires you to take the
7 or
42nd Street Shuttle across to Time Square, and then transfer to the
1, 2, or
3 down to Penn Station. Those trains are absolutely packed at any reasonable hour, and luggage makes that ride that much worse. And before you suggest getting a cab, you're in mid town and cabs cost $$$ and take forever.