We gave up the ship on USAir after the federal reg was lifted that mandated other airlines to accept tix from bankrupt carriers. Since that time we've flown on AirTran. Although the price is right, unless you book business class there is no preassignment of seats until the day before. I understand SW is even worse with their system: call after midnight, get assigned a line, yikes?
The one time I couldn't find internet access to pick seats (the AS Mu desk said their policy prohibited guests from using the hotel internet?), when we checked in upon arrival @ the airport 6:30 a.m., we had the very last seats in the plane. Noisy, bumpy & w/o a window, what a treat!
Even though I'll be on a cruise the day before we leave, I'll make sure to find an internet connection.