When I went through Gatwick (North) last week the arrangements were dreadful. Queues (not moving), one manager shuffling people around so people could make it past the initial check, and then one of the perfume buggies arrive with a rather attractive blonde driving it.
This didn't distract any security staff when it arrived to be checked until the lady driving it showed some stocking top by accident and then it was swarming with security officers to be checked!!!!, this casued the queues to get longer. Only 2 out of the 5 machines were open (4 machines if you count out the Fastrack lane - which was closed as well!).
Heathrow - never a problem....well only once but Burger King caught on fire so that's an excusable reason!