I think I've only flown to FL twice - once as a child and once as an adult. All other times we've driven. We always, both when I was a child with my family and now with my own family) take three or even four days and make it part of the trip. Even coming home for me is not a big deal because it lets me ease out of out trip. I hate to leave as it is, so having a few days that I'm on the way home but still technically "on vacation" helps.
We always take I75 which I think adds a couple of hours but to me is a much better highway, plus the Along I75 book is fantastic!
Next time, though I think I'm going to try the Auto train. This is probably the last time I'll get DH to go to WDW, so the kids and I will start doing the tip ourselves (unless there is a miracle and he is converted in January

)