So, in our circumstance, we basically did a race last year. Friends were meeting us for a longer weekend (4 days). Despite what I said earlier about stopping after about 6 hours of driving, in this circumstance, we were able to leave a bit earlier in the day, and drove straight thru. As mentioned, truck packed, gassed up, ready to go. 8 hours door to door, including a quick dinner/gas stop. I have all the luggage I want, I have my own car, we are good. My daughter has her special pillow, My son has two light-sabers, and my wife has a suitcase full of just Disney hats.
Our friends flew. Gave themselves an hour to get to the airport and park. Planned to arrive two hours before the flight to gather their luggage, get thru security, and reach the gate. Three hours into the process, and they are still on the ground. They packed light, not a bad thing, just saying. The Flight is about 1:30 - 1:45. Five hours into the process, they have their luggage, and are at the car rental agency. In short, it was just about 6 hours door to door for them.
Granted, they were not all stuck in a car for 8 hours. But my family got to bring what they wanted, eat what they wanted, take their shoes off if they wanted, and it was significantly cheaper for four of us to drive than fly.
Best part, we took some of their luggage back with us so they could save the luggage fee. Too bad we did not think of that before we started the trip.
Here in Charlotte, about once a year the TV news will ask the question "Is it better to fly or drive to Atlanta". The answer each time is that it is about 4 hours either way.