Perfectly executed on the BA430 LHR-AMS yesterday:

'Group 0 Boarding' already showing on the screen when I got to the gate. Was let in and asked to wait by the stairs.

5 mins later - Group 0 called.

Another 10 mins and Groups 3/4/5 all asked to check in any hand luggage due to a full flight.

5 mins later, I was invited to go down and board. First to board, with only 3 people following, 1 in a wheel chair. Must have been another 10 mins before everyone else arrived.

To top it all - I even got a personalised 'welcome back' when they served breakfast :-)

However, all my good luck was all short lived when I got to AMS - total chaos... Several hundred people in 1 queue and apparently only 3 immigration officers checking passports... Took more than 1.5 hours to exit!! And it was only a 45 min flight.