From the seating plans I've seen the GA area won't be as big as the ones here in Europe. There are even seats at both sides of the GA pit so I guess it will be smaller. We'll find out in a few weeks.

Last time I went from NY to NJ, I took a bus/coach from Port Authority and it only took 20 mins. As someone said before, that's the best option. Not sure how easy it will be to go back to NY after the concert though.