Similar discussions about the inefficacy of fast-track security lanes here and here.

FWIW (nothing to do with AC though), the most sensationally rubbish 'fast track' security lane I have encountered recently is the new one at DUB, which is basically an elaborate practical joke by the airport authority. It consists of a separate door through the wall into the screening area - but when you get through, surprise ! it turns out there is no dedicated machine processing 'fast track' passengers, and you have to walk over to the regular lane and try to insinuate yourself into the queue in front of all the truculent Ryanair passengers coming through the other door, while the staff just stand there giggling into their sleeves at your discomfiture.