I live right next to Stansted and commute in to London regularly, you can be in Liverpool St in about 45 minutes on the train, which is quicker than trying to get from Heathrow to The City on the tube! Driving, even at 8am it takes 15-20 mins to get to the M25. Its surrounded by fields and sparsely populated, compared to Heathrow.
Anybody tried driving from Heathrow to City Road recently?? At any time of the day it can take 2 hours through West London. Its a nightmare.
And then, we have Manston.... a whacking great runway, ready to go, again, surrounded by fields and room to expand.
For anybody stood outside looking in on this situation it just seems utterly bonkers.