Phileas
With the greatest respect I'm not missing the point at all. Other than that first line of your latest post I agree with everything you say.
I don't believe that SEN is a natural choice airport for a NQY-LON service and have never suggested otherwise. In showing the relative train travel times to LON from each airport I was merely trying to be helpful in illustrating that quotes such as "Southend - not really a london airport" and "And Luton is neither!" are not to be taken seriously. Mind you perhaps they were intended to be rather tongue in cheek remarks anyway.