I still say they should resurrect the LHR-LGW dedicated high speed train link as well as part of an integrated airports plan.
Or even re-visit the option for a non-dedicated, non-high speed one. I'm told by my colleagues in the rail sector that it is possible and many studies have confirmed it as a southerly line runs close to Feltham and trains could route from LHR via Clapham Junction to LGW.
The same new spur line from near Feltham would allow a second HEX line into Waterloo - much more central London than Paddington and platform space will free up there when the Eurostar moves to St Pancras in a couple of years.
Too much to ask for an integrated transport approach?