With a child that age I liked driving. With the amount of stuff I had to bring it was just so much more convienent to load everything in the car. We did the drive many times with DD from the age of 9 months, then every year until she was about 7. Then when DS came along we drove twice with him from the time he was 8 months. When we finally did fly last year the kids did great, but they were 8 and 3. DD had a lot of problems with her ears hurting even though she was drinking, chewing gummies/gum. Nothing helped her. DS was fine and slept most of the time. We will continue to fly but I loved driving and we had it down to a science! When the kids were young they would sleep most of the time while we drove. We would do the drive straight through leaving our house by 4am arriving at WDW by 9-10pm. We would get a good night sleep and be ready for touring the next day.
Good luck!