Jarvy - guess the difference is that some airports learn and make changes. Even Dulles, possibly one of the worst I have experienced, actually now has a decent system in place for both arriving and departing pax.
T5 security has never worked well IMHO and the 'fastrack' system is more often than not anything but fast. Security personnel working there are clear that BA and not BAA decides the set up and how fastrack will operate ie; one queue or two. The lack of space does not help, of course, with security checking area pushed into a long thin layout which is far from ideal. Options for change would appear rather limited.