Total agree with gdiphil , queues form to long snakes due to insufficent staff to process pax at checkin and security. If BAA realy wanted to make money from the retail outlets they should process you through security far more quickly. ie more scanners and teams of checkers. They could also push carriers / agents to keep checkin queues short by fineing them. Pax stress starts on arrival at lhr with the poor layout, signage & cramped conditions.
Pax should still arrive with plenty of time why rush and stress.