1. Can't look them up on a different website
No idea there - I always book via Southwest (or their business website). Not a big deal.
2. Can't pick your seats (true? not true?)
You sit wherever you want. It's open seating, one class. Some people love this, some people hate it. Entry order is based on when you check in (which you can do online 24h before your flight), though if you want the early numbers (it really doesn't matter that much), you can pay an extra $15 per trip for super early check in. This is useful if you want the extended legroom seating (overwing exit rows).
3. Not convenient - they don't fly out of our local airport, so we'd have to drive 2 hours. Which we do 90% of the time anyway.
Well, that's annoying. Can't help you there. :)
But...there are 4 of us, which makes it less convenient. And...my kids are young enough, I need to sit with them.
No problem at all. If you've got kids under 6, you board between A and B groups, which means you have pretty much your pick of anything past the first third of the plane. It's no problem at all to get a set of family seats, in whatever configuration you want. Also, in general, nobody complains about you saving seats for family members if they're a bit behind you in the boarding line. Boarding is pretty laid back.
So what's the bonus with Southwest?
I fly them for several reasons, many of which won't matter to an awful lot of people on this forum.
1. "No Bullshit" pricing. What's listed is what I pay (and I'll usually toss in the $15/direction early boarding if I'm on business travel, and cover it out of pocket, because I like exit rows for working on a flight). I don't pay per luggage item. I don't pay for various extras. I don't like being nickel and dimed, so I won't reward companies that do it with my business.
2. The free luggage means that people check their damned bags, instead of trying to cram everything in carry on and overhead bin space. Gate checking and the subsequent reverse flow and boarding nonsense is basically eliminated.
3. Southwest's boarding is the fastest option out there (Mythbusters tested this pretty comprehensively, and while not the most satisfying, it was the fastest by a significant margin).
Reasons other people may not care about, but are important to me:
4. Boeing flies a fleet of purely 737s. This has several subpoints:
4.1. This means that their maintenance folks and crews aren't switching around airplanes regularly (the different revisions of 737 are pretty close to each other), which means they should be more familiar with the quirks of the airframe and have a better safety record. Their safety record is excellent, which says they're doing something right.
4.2. I prefer to fly on big birds over the regionals. I have no particular complaints about the CRJs in terms of safety, but I simply don't like flying on them. Every CRJ200 I've been on has a subtle undamped dutch roll at cruise, and it drives me nuts.
4.3. I refuse to fly on Airbus unless I have no alternative. "If it ain't Boeing, I ain't going." I fundamentally disagree with their flight system control philosophy, and AF447 crashing a perfectly solid airliner into the ocean is due to exactly the sort of UI confusion that the Airbus design philosophy creates. There is no ambiguity in Boeing aircraft about what's being commanded, and I firmly believe AF447 could not have happened in a Boeing airliner, as the full nose up command would have been blindingly obvious to everyone in the cockpit (flight yoke in your nuts). I don't think a pilot would have inadvertently commanded that either.
5. US carrier, flying US airplanes. The 737 is built in Boeing factories, by Boeing craftsmen, in America. I'll support that when feasible.
6. Employee-owned, and profitable even when the other airlines were declaring bankruptcy. Southwest doesn't have any reasons to take shortcuts to save money, and the employees are rewarded heavily based on the company profits. I've seen this in how descents are flown - it's rare to see someone flying a partial spoiler descent on Southwest - either it's clean all the way down (very efficient on fuel), or they're getting crowbarred ("toss a crowbar out and beat it down") and are on full spoilers, and that's just how descents to certain airports are flown. I don't see the laziness I've seen on other airlines with partial spoilers on the way down and getting the airplane dirty really early into the landing.
So, basically, that's why I fly Southwest. If they don't go where I need to go, I'll pick another carrier, but
I support what they do, I like how they fly, and if I am going somewhere that they don't cover, I'll pick a carrier that flies a pure Boeing fleet over someone who flies an Airbus fleet or a mixed fleet.