We have flown Southwest many times. Like most things, it has its good and bad points. On advance purchase fares, i.e. 21+ days out, they are usually cheaper than the competition, at least in Texas. Also, getting refunds or changing your flight schedule is easy with them.
On the downside, they do not have assigned seating. At the gate, we call it the cattle call. You get a boarding pass and they take groups of passengers for boarding, 30 at a time. For refreshments, you get peanuts or pretzels and a soft drink or some other beverage. Alcoholic beverages are available for a fee. This used to be a place where SW skimped, but in the current area of cost cutting at airlines, this seems to be on par with what the other airlines are doing.
Southwest is also known for having a very relaxed atmosphere and fun flight attendants (they used to wear hotpants). Sometimes I'm in the mood for that and sometimes I'm not.
Bottom line, SW is usually cheaper. Here, they have the most flights, particularly to smaller airports, so I use them a lot for business or when my schedule is inflexible. Otherwise, I prefer to fly one of the other carriers (no cattle call, more professional, etc...).
Hope this helps. You can also watch SW at work on the show "Airline" on A&E.
