I have a particular CME meeting that I attend every year. I had taken Frontier because it changes planes in Denver instead of DFW. I have had issues with DFW and short layovers and delayed incoming flights. I am flying from IND to SNA. Frontier has been OK in the past. Some of my most interesting stories involve this particular trip. However, this year, I discovered that there were no return flights scheduled for April for the SNA-IND route. There are flights from SNA to DEN, of course, and flights from DEN to IND, which is the same as I've done in the past. So, this year, I am taking Southwest. Well, Southwest has already changed the flight time. For some unknown reason, flights were twice as expensive on the day I wanted to travel as on the day before. Not sure why. I am traveling the Monday after Easter, and wanted to leave the Tuesday after Easter, so, my trip is 1 day longer, because the meeting starts Wednesday. The bottom line, I don't see much difference between Southwest and Frontier, except with Frontier, I had assigned seats.