My family used AirTran for the first time on our last trip to Disney World- we actually used another airline on the way from Baltimore to Orlando, but then used AirTran for the return trip so we could compare the two airlines, and AirTran won that battle hands down.
Our flight was on time, and our luggage arrived safely- obviously 2 very important features when flying with a family in tow. Also, the staff could not have been nicer- we had a car seat to install, and the flight attendants offered to help us get set up, and asked if they could hold my son while we got everything situated- my son was cranky at the time, so this was very appreciated.
They handed out snacks and drinks freely, and stopped by to wave at my son and offer extra snacks for him to keep him entertained, which was very nice.
The airplane was immaculate, and seemed very new inside. We had some turbulance on our return trip, which obviously has nothing to do with the airline, but I was impressed at how the staff helped calm any nervous passengers, and the captain frequently made announcements to prepare us for any weather ahead of time.
All in all, we had a great experience with AirTran- so much so, that we booked with them exclusively for our upcoming trip this December. My only issue with Airtran thus far is that they have changed the flight times for our flight 3 times now, and rebooked us automatically each time. I was never notified of any of these changes- I only happened to notice by looking at the website myself. When this happened, I called customer service, and they were more than willing to rebook on a flight that better suited my times with no charges- in fact, because there was a sale on fares the one day I called, I actually got a credit! They are very helpful when you call, but I really wish I could be notified of changes a little better.