I would venture to say that being put in an interrogation room for a few hours cuts into the flight-time advantage of flying.
As it is, driving a long distance vs flying sort of works out this way. If I want to visit Denver Colorado from my home here in Canada, I have a choice of travelling by car or flying.
If I drive, it's a good solid 10 - 11 hours of driving from where I live, with a moderate stop at the border to answer a couple of questions. I get to see the beauty of the country (Wyoming is particularly picturesque), and the cost in gas is pretty OK. I can stop wherever I want, eat whatever I want, make phone calls, etc. It's a very pleasant, if time consuming, way to travel. My trip back is generally just as pleasant. If I leave at a good early time in the morning, like say 4 am, I can be at my destination by 3 or 4pm that afternoon.
If I fly, I have to get to the airport a good hour and a half before my flight leaves, so that I can get in the line for check-in, and then in the line for security clearance. In the security line I have to do silly things like take off my shoes, belt, have someone poke through my carry-on to make sure I don't have large liquid containers or too much tooth-paste. At least on the Canadian side of things this is a polite and generally stress-free process.
Then for the flight itself I have to endure sitting for two and half to three hours in a big metal dong full of dead air and the sneezes and coughs of my fellow travellers. We eat some kind of awful snack thing and half of a beverage, and fsm help you if you need to use the washroom on the plane. Once you get to the other end of the journey, you have to walk at least 1-2 miles through the terminal to reach US customs, where you again have to stand in line to have someone very rude and surly check that you are good to be in the country. Then you hop the tram down to where your bags are, and negotiate the rental of a car, and then start the journey from the airport to the city proper. This adds at least another 2hours from getting off the plane to getting to where you were going to the journey. If the flight leaves at 10am, I can be at my destination by 2:30 or 3:00 pm.
In total, I've spent 6 hours to fly uncomfortably by air, get treated like a criminal, eaten terrible food, have seen nothing of the coutry's beauty, and paid more for the privilege of doing so. And I ended up at my destination only slightly ahead of when I arrive by driving.
Sure, driving took longer, but cost less, gave me more freedom, less hassle, and more of a sense of seeing new places. I'll take driving over the experience of flight anytime.