We have drove the 15+ hour trip once and flew twice at this point. We are driving down in the end of September. Our first trip, we flew and it was with all four kids, DH, and me. Kids were small then, 8 months, 5, 6, and 7. The next year we drove our Toyota Sienna, packed to the gills, and drove all night. DH drove a little more than half way and I slept. I drove to Daytona and we had breakfast at IHOP, was on the beach at sunrise and in bed before noon. It wasn't fun but it worked and was much cheaper even with the hotel cost. We did drive straight through coming home but it was daytime and we stopped plenty along the way. I loved having our vehicle there. It was so much easier with four kid an a stroller. The third trip was an anniversary trip with DH. We flew due to time constraints. I am a teacher and had to be back before school started plus two tickets are much cheaper than 6! I didn't miss the car this time as the buses aren't bad when I'm only responsible for myself. Lol!
Now, DH and I are taking the youngest, now turning 5 for his third trip and the first one he might remember. The older kids, now 11, 10, and 9 have made other trips with their grandparents. I'm still having to justify it a little bit to myself though. We are driving again. I wanted to fly but the costs are making my choice. I can drive for about $500 excluding wear on vehicle etc but plane tickets were going to cost us at least $1000 and then I would have to do without my car with a 5 year old who can be exceptionally cranky when he is tired.