Arrived at 06:40 last Sunday and waited 80 minutes to go through the fast track line. In fact, fast track was much slower than the normal non EU line as I was getting out of the line at the same time as people who arrived 1/2 an hour after me.
Many of us in the fast track line were joking about how the olympics will be a complete fiasco. Only 2 booths were processing fast track while the staff processing the UK/EU were just sitting there staring at an empty line. Finally an American couple about to miss a connection headed to a non fast track window when they reached the front of the line and managed to convince that border officer to process the fast track line. After that, the line moved a bit faster with 3 windows open. All in all, completely unacceptable.
Also, BAA staff was never checking boarding passes or asking for the fast track flyer when people were joining the queue.