When East Side Access is completed, it will open up many doors for those who work on the East Side closer to Grand Central Terminal. I believe that there are several law firms that are much closer to Grand Central Terminal than to Penn Station. Not just for the sake of jobs, but sightseeing, for those people who are visiting museums on the Upper East Side, it will just be a matter of taking one subway ride to GCT.
When LIRR starts running to Grand Central Terminal, does anyone know what will be the approximate percentage of trains that will stop serving Grand Central Terminal? When trains are rerouted to Grand Central, this will help enable the MTA to add Metro North stations along Amtrak's Hellgate Line and start running Metro North trains to NYP, helping reduce the commute for many people who live in the East Bronx, especially Co-op City who need to go to Manhattan.