My biggest problem with Southwest is they routinely lie about flights, telling you they are going to be on-time when they know otherwise. I'm sure other airlines do this as well, but Southwest seems to always have the most confusion and disorder in the gate areas, perhaps because they will sometimes have 3 or more flights all posted out of one gate. I had one flight where the gate agent just got up and left without saying a word to passengers about why the flight was delayed or how long it would be. Turns out the inbound crew was late and they'd known about it for hours, yet they still insisted the flight was "on-time." Only 30 min after the scheduled time did they finally acknowledge we were late.

The check-in lines I see for WN also make me cringe sometimes, but fortunately I almost never check bags.