I was one of those with big Airtran issues (two different trips). If you do book with them (they are cheap, no doubt), try to book non-stop if at all possible. Readers Digest version: My connecting flight in Atlanta left early, and even though we were there, they wouldn't let us on the plane becuase they didn't have time to change over the luggage and still leave on time- so they stranded almost 100 people! Ironically, I only had carry on luggage
Also- check your flight reservation often for changes (this last trip they didn't notify us of a significant change).