I totally agree with you - but for me I think it's much easier to drive with children that age, than it is to fly. You can overpack if you want to, you can go at your own pace and stop as many times as you want to, you don't have to worry about the children crying on the plane, and it's not as frantic trying to get from gate to gate, and worrying about luggage getting lost.
I know some people think I'm crazy, but by the time you get the airport early, wait out any delays, then there is the layover in another airport, then wait for your luggage in the arrival airport, then wait for shuttle or rental car and finally drive to resort - what sounded good as a 3 hour flight has suddenly turned into 7 or 8 hours (yes, I know the drive is much longer than that!). So while you are saving some time by flying, it's usually not as dramatic as most people think. And if you're flying in the summer, beware of afternoon t-storms almost every day that cause major delays at the southern airports!
To sum it up, I'd definitely be driving (fighting DH all the way, he HATES to drive!! ) Enjoy!