Southwest is the BEST BEST BEST! You're right they don't charge change fees, only if the price of the ticket is different do you pay the upcharge. The only thing I don't like about Southwest is the open seating. Oh my God, it's a plane, we are all going to the same place, sit down, shut up, let's go! You give people an entire plane to pick from it's like letting a kid loose in Toys R Us with an unlimited balance credit card. People turn into blithering idiots that can't find their way down a straight aisle!!!!
I flew with them recently... middle seat in the bulkhead row was open. I like bulkhead if I can get it, there is extra leg room. I sat down and these two women said they were traveling together. I said, oh, do one of you want the center seat? I would have taken aisle or window, didn't care. No, they were quite comfortable but they wouldn't be able to talk with me sitting in between them. HA! I put my bag in the overhead, plugged in my headphones and closed my eyes. Too bad ladies... you didn't pay for 3 seats, you don't get 3 seats! Sheesh! That's my only complaint! Otherwise I like fling Southwest whenever I can.
I have also wised up and pay the additional $10 or $15 to get an early boarding pass. Then I sit where I want and no one bothers me because I'm there first. LOL