Hudson Yards is impressive. Philly has a version of its own ready to go with Schuylkill Yards (
http://schuylkillyards.com/) and it sits right on the Amtrak line. Senior management could live part time in NYC or DC and commute to Philly pretty quickly.
Philly's also go Comcast and the second strongest university scene behind Boston. Plus, the city is affordable. That's an important factor for its employees (as they call out "cost of living" in the RFP).
Honestly, I think Philly is probably the most competitive city for the bid outside of Chicago. Philly's location on the east coast is a pretty huge asset, especially now that Boston, NYC, and DC are so expensive and Philly has remained affordable.