I think it depends on how satisfy are you with your current job. If you come from a low-end regional, then AirTran is certainly a step up. If you come from a reputable, decent QOL, live in base, good schedule regional, then you have to think about a few things.

AirTran operates just like most regionals, with tight turns (29 min. to 40ish min.), very high utilization of its a/c, FO running outside to do walkaround just when the a/c pulls in from the last flight. It will be somewhat similar to your current regional working environment. The layover is definitely better, with usually 12-20 hours, no reduced rest (except stand-up or red-eye or hi-speed). Crew scheduling is very solid, usually will not try to pull a fast one, and they are cordial, in my opinion. If you are on reserve, your guarantee is 70 hours, and when you accumulate more than 4.0 hr. credit each day you're working, it goes on top of that guarantee. However, they have the option of removing your reserve days without pay, so as to cap your earning power.

If you like to stay home, not fly, earn maximum hours, AirTran is not the place for you. Most guys fly at least 85-90 hours a month, and get about 12-14 days off. There are very few senior "good" lines, as in 20 days off, so keep that in mind. You can make some coins, but you definitely work for it. Also, the number of 4-day trip is astronomical, followed closely by stand-ups, they do that to keep the commuters happy. Most of the 4-day trips will earn you about 17-23 hr. credit, with a 4 hour. minimum pay/day. Stand-up pays usually about 4 hr, depending on block. You will not get ANY sleep on stand-up, with a turn time of 5 hr. on the ground, but you will be given a hotel room. You should sit reserve anywhere from 4-6 mo. on 717, and perhaps longer on 737, and that's the worse scenario. Morale is low at this point, with the new BOD election, TA still nowhere in sight. Hopefully it'll pick up next year. This airline is run very lean, without much fanfare, so don't expect the "major airline glamour" when you step in the door, because you will be disappointed.

In my opinion, there's no such thing as too much jet PIC these days. (just ask the next kid who wants to interview at big D but never touched a jet before). AirTran is definitely gonna be here for a while (if we don't buy somebody soon, somebody's gonna buy us soon), and that's a very honest opinion. So take the interview, sleep it over, and think about it. Many majors are now hiring as well, but funny how they won't call you when you're at a regional, but only at a comparable major airline.