I flew from Geneva to London City Airport the other day. Check in closed 45 minutes before the flight, and it's so convoluted to get through the airport that after checking in right at the deadline, I had a brisk walk through the airport for 30 minutes to arrive halfway through boarding. I would not want to arrive any later, and anyone who didn't want to rely on short lines at security moving fast would be well off to arrive at least an hour before takeoff.