I agree that AirTran is a good airline with newer planes and very helpful and friendly employees.
The only problem I have had (and many other Dis members) is that they are constantly changing their schedules. We normally take the first flight out in the morning and this only changes a few minutes either way, if at all. However during the day AirTran sometimes makes drastic changes. Last June we debated on whether to take a return flight at 2pm or 4pm. Luckily we decided to stay a little longer at WDW and took the 4pm. Sometime later AirTran removed the 2pm flight from their schedule and had people scrambling. I have read numerous posts about people not knowing about the changes but I have always received an e-mail about it, although it comes way after the changes have been made. Now I check their on-line schedule almost weekly when we fly them to see if anything has changed.