Well, I'm guessing it's about a 13 or 14 hour trip for us driving, and 1 and 1/2 hrs. flying. The thing is, you do have to figure in time spent waiting for delayed flights, the drive to the airport and gas to get there, parking (which can really add up!), time spent going through security and check-in, and all that other "time" as disneysteve mentioned. It can really be frustrating having to be at the mercy of the airlines and their time schedules that aren't always "on time".
I love the freedom that driving offers to me, and especially the knowledge that I won't have to worry about the weight of my luggage on my return trip (from all those souvenirs!). I just load it all up in my car/truck/van and go! And my husband (God bless him!) loves stopping at all those tourist trap places on the way down. That does add a bit of time to our schedule, but he really gets a thrill looking at all that kitchy stuff, and he's the one paying for our trip anyway.
So I guess it's to each his own. It just is better for some folks to drive, and others to fly.