I used Air Tran last month from Pittsburgh. 24 hours before, you go onto their website to check-in. A map of the plane will come up and you pick your seats. Both ways I had almost the entire plane to pick from. You print out the boarding passes. On the return trip, I had my laptop and did the check-in and selected seats but could not print out the boarding passes. That was no problem, I picked them up curbside.
There was no curbside in Pittsburgh but there was in Orlando. In Orlando, I drove up, the skycap printed and attached the bag checks, took the bags and printed the boarding passes. We did not have to go inside with the bags, the skycap took care of it. Then I returned the rental car. Their gate area at MCO is in a new section, it's very nice.