The security checkpoint situation at PHL has improved considerably, there is a new checkpoint between D&E with many more lanes, and this also means E is now connected with the rest of the airport.

With the fact US has lost a number of flyers, I often (when not checking bags) go through security at B or C for flights out of D or E, and there's rarely much of a line. There's also a fast moving walkway post security to get to D or E easily.