It depends. I've done both. At @ 540 miles from the NC/SC line below Charlotte, that's not a huge distance. It's @ 620 miles from Clemmons, NC, and it takes us less than 9 hours. That's with 2 stops, for fast food and fuel. We figure it this way (rough time estimates):
Drive to GSO and park - 45 minutes
Arrive before the flight and check bags - 1:45 minutes
Flight down - 2 hours
From MCO to WDW - 1 hour if we're lucky.
So, the flight process takes us 5.5 hours, if everything goes perfectly. Delays or cancellations or overbookings add more time.
The drive is, let's just say 9.0 hours.
So, we lose 3.5 hours each way, but have our own car at WDW for DTD or AK visits, or even (dare I say it) off-site visiting. If the car gets 20 mpg, that's @ 60 gallons round trip @ $2.50 per gallon, so $150 in gas. (No, I am not figuring oil use or tire wear. This is just a quickie example.)
If we fly, and get a decent GSO fare at $200 each, that's $800 for 4 of us.
(not including parking at the airport)
So, $800 - $150 = $650 savings, for an extra 7 hours travel time, means we 'earn' $90/hr for the drive time. I wish I could make $90 an hour at work!
So, for us, driving makes the most sense. In fairness, we do time our departure to avoid rush hour traffic along the way. Also, we can take along lots of stuff that normally wouldn't come on the plane, due to bag limits.
It comes down to alot of factors: location in NC, finances, length of trip, personal choice, etc... but since both CLT and GSO have TERRIBLE pricing to MSO, it looks like we'll be driving, at least for the immediate future.
Hope that helps.
Robert P