Even when I travelled Wilmslow to Bedfont Lakes (within walking distance of Heathrow T4 through the Hilton) I didn't find flying much quicker, and broken up into lots of annoying bits, and the idea of being able to work at any point was generally laughable. Yes, I probably got to the airport sooner than I needed to, and then the return flight was often an hour or two later than I could have wanted, whereas there are three trains an hour from Euston I can use. At the time I wasn't allowed to fly anywhere without special bean-counter permission whereas I could buy a train ticket myself, so it wasn't normally worth the hassle of trying to fly.
On another occasion I was arriving in Paris Gare du Nord on the RER, having flown from Manchester, and I noted a Eurostar arrival which I could probably have been on by leaving home at about the same time as I did. On this occasion I was no longer working for IBM and my new employer didn't mind my flying in the same way, but also because it was considerably cheaper than the train.
So my experience, even living within close proximity of the airport at one end and walking to my destination at the other, was that flying was little quicker in reality and a lot more hassle.