Pros: 1. Cheap prices
2. Purchase tickets one hour before flight. What airlines allow that?
3. Multiple flights
Cons: 1. Dirty floor on airplane
2. Too many people
3. Staff throws your bags around without care
4. Some staff are incompetent
Usually I fly Southwest because it is the cheapest and I will continue to fly Southwest. I did have somewhat of a bad experience the last time I flew back from Vegas. My husband and I made it to the gate and the plane haven't even left, but they would not let us in even though the plane didn't take off for another 10 minutes. Then they had us on the wait list but the worker never put us officially on the list like they said they would and my husband and I kept missing flights after the other until we finally spoke to someone with a brain and said that they couldn't put us on the wait list for some reason. We almost miss all the flights and my husband and I ended up on different flights home because of their mistake.
Nevertheless despite all the drama, I will still use them because it's cheap and there are a lot of flights available.