I'm bracing myself already for the tirade I'm probably about to unleash, BUT, as a simple SLF I have to say if I was a passenger on an aircraft which suddenly experienced severe engine problems I would be much happier if the flight crew landed on the nearest available runway able to accommodate it. I would not feel very secure if they chose to turn away from the nearest available runway and fly me over densely populated urban areas with, lets face it, nowhere to go if the engine problems suddenly became even worse. I understand there are any number of procedures to be followed, but how could they be sure they were not going to experience a total power failure? Also, under what circumstances would they have chosen to land at either Luton or Stansted if this particular situation was not deemed serious enough to warrant doing so?