It really depends on a number of factors. I've done both, and would do both again.
Generally, my first choice is to fly - provided I can get a good enough deal.
My first rule of vacations is that time is money. True, driving will give you a car to use, but that should not be your main consideration. You can just as easily rent a car, or rely on Disney transportation (Yup, I've done both of those as well. You can also rental car of a day - but that's not alwasy worht the hassle.) Time is money on any vacation, so if you can get a reasonable deal, then renting a car is likely worthwhile - but if you stay all deluxe - you may not use it much. (on property) At the mods and values a car is a much bigger asset. Driving gives you the choice of a few places along the way.(see below)
Another big factor is how much time you have. If you are retired, say, then driving becomes a more attractive option. If you only get a week of vacation all year - driving is less attractive. (Just citing two potential extremes.)
Driving is only worth doing if you see the driving time as PART of the overall VACATION. If you see it only as a means of getting from point a to point b - you are better off flying.
Generally speaking, don't drive to 'save money.' the espense of driving goes far beyond gas, tolls, meals, hotels, oil changes...you also have to factor what you paid for the car ($20,000 - $30,000, more? less?) and how many miles (say 150,000 total) you expect to get out of your car. divide and you get an estime of what each mile in the car costs - not counting in expenses - or you can roll some basic ones into the equation too - like oil changes. UNLESS - the airfare deals are really bad, and you have enough people going. Though with your staying overnight to fly...that's an important factor.
Also consider the traffic you might encounter. If you can drive inthe middle of the night - so much the better. Driving with certain family members (Small kids, annoying adults, anyone prone to car sickness, anyone with a 'small' bladder or other health issues) can also add to the hassle. Getting stuck in a traffic jam - to me - is far worse than an equal-amount-of-time airport delay.
Conversely, flying has it's own set of hassles. Including bag limits, retrictions on liquids, medical equipment. If you can get a direct flight - then that's a bigger plus for driving. There's always a very real risk with a two leg flight that a delay will really muck you up - perhaps even leaving you stranded. This is true in summer thunderstorms, hurrcaine season, and winter blizzards. Last year my family all managed to escape a blizzard - but we were just lucky - several of us by mere minutes - as airports shut down. Other times we've been stranded in Orlando.
then again, A blizzard(/rain/hurricane) can stop a highway too. THAT happened to us many years ago. We were stuck for days (It was many years ago) in a place that rarely sees snow. Your best bet with driving is some flexibility to leave a day early or late to avoid bad weather. (Then again, that's how some of us escaped the blizzard this past winter, too.)
The food along the way to Orlando is mostly really bad. REALLY bad. If you drive, consider a cooler with a few healthy choices for the first six hours inthe car. Otherwise, you are well to consider your stopping points ahead of your departure. Sometimes small towns offer great choices, sometimes cities are easy. If you stop overnight, you can ask the staff at your hotel what is good. (Avoiding most common chain dining is wise.)
If you drive, you will likely also need some recovery time on either end - especially if you drive straight through. WE recently did a similar drive - and went all the way to Daytona Shores beach (Excellent Hampton Inn!). It was then only an hour to Olrando, and we had a day to rest. St.Augustine is also a nice place, but it's more like 2hrs from Orlando. both are onthe coast - so you get to see ocean.
I also like MCO. Checking in at the end of the trip can be a hassle, but mostly it's a pretty nice airport. As airports with chain dining go, it's not too bad. There are also a number of shops.