My brother-in-law lives in Newtown and always flies out of PHL, if at all possible. His only concern is the worry about traffic on I-95. In fact, one time my wife and I were going to PHL and there was an accident on I-95. We crossed over the Betsy Ross bridge and went down Rt 130 in NJ and crossed back over the Walt Whitman Bridge. Fortunately, we had allowed some extra time to get to the airport.
Too bad there isn't enough demand for flights out of Trenton. It seems every time someone starts up there, they last about 6 months to a year and then cancel.