Great points. Also note that because they don't have reserved seating, if you're last to board on an overbooked flight, they'll bump you with no compensation and you'll have to wait for the next WN flight with empty seats, which could be awhile since they don't interline! And there's basically no FF program!
Now, if you have kids (or even teenagers), it's great because you can pre-board the entire family. Most of the time you can even sit in the exit row with your kids (if they're quiet) because the flight attendants are so busy being chirpy and cracking jokes they don't notice. WN is not exactly the nation's safest carrier, what with their cowboy pilots crashing into Burbank gas stations and Chicago inner city neighborhoods.
US is a far better alternative for business travelers, with reserved seating, a world-class FF program, non-stop flights from three hubs, in-flight meals* and drinks*.
* for a small fee