Take Amtrak--NJT is a commuter line, which means that it is slower, and makes all the local stops. Also, no place to stow your baggage. Also, plastic bench seats--You'd get off at Trenton, go up the steps, buy a SEPTA ticket, then walk down the steps to the SEPTA train(which connects with NJT, meaning that it waits). Then you'd have to change SEPTA trains again at 30th Street for Wilmington, but this train doesn't wait--No food or water on any of the commuter trains--also, commuter trains run less often on weekends and holidays, and there are no reservations--

If you use AAA, you can get a fair discount on the Amtrak tickets--but you have to buy them at least three days in advance.