Just for fun, let me toss this one out ... I flew Ryanair for the first time last week, and out of Stansted, their busiest airport. The cost was $22 + tax each way, and I probably paid more than most of the people on the plane.
Ryanair has the same seating policy as SWA, but they don't use the ABC system, they number the boarding passes in order of checkin, and you are expected to line up in numeric order. (This allows people to arrive at checkin early, but linger at the duty-free and spend money.) They also limit their turnaround time even more than SWA, but they are too cheap to pay for the use of jetways; you walk out onto the runway to board, and board through both doors simultaneously. Luggage is SEVERELY limited; you get one carryon piece weighing up to 15 lbs., and one checked bag weighing up to 33 lbs. (you can check a heavier bag, up to 75#, but each add'l lb. will cost you $8. ... Yes, buying an extra ticket has been tried; no baggage allowance for one person's second seat.)
Lots of people in Europe grouse about Ryanair's terrible customer service, but they fly them anyway, b/c they really are dirt cheap (they often have "1 cent" sales, where you pay just a penny + the taxes to fly each way.) They are especially notorious for their baggage handling; if they don't get your bags on the plane at your originating airport, and they discover you are due to return in only a few days, then they will just not bother to send it on; it will be waiting when you get back! People who use them for business travel know they have to carry their equipment and check their clothes, just in case.
Interesting enough, though it was Easter weekend, and the plane was full of kids, there were no scenes about split-up families, and no other scenes at all. The reason is rather simple. UK and Ireland law (and it probably applies throughout the EU) is that in case of emergency, children 12 and under MUST be seated adjacent to an accompanying adult. This means that Ryanair preboards all children up to age 12, and they have chosen not to accept unaccompanied children at all. Kids and their parents boarded first, followed by anyone physically disabled, and then the main line was released. All kids are asked their ages at checkin, and the boarding passes for the family are a different colour if there are kids in the group. If you have a white pass, you don't get through the boarding gate ahead of the line; if you try it, they send you directly to the back of the line. It was flawless, and we were wheels-up in 10 minutes flat, and this was a 737, too. The FA's were not cheerful or peppy, but they got the job done.
SWA preboards the littlest kids only b/c US law says that kids 5 and older do not have to sit with an adult in the same party. It would seem to me that if kids 5 and older being separated is an issue for you, then the proper thing to do is to write to your Congressional representative to try to get the law changed. (I think it should be, personally, mostly b/c of equipment changes on airlines w/ assigned seating. Separated 6-8 yo's usually end up bothering other people.) This would not apply to kids flying as unaccompanied, since they are at least nominally supervised, and all sit together in the front rows.
BTW, wouldn't it be great if we had domestic "no-sales-tax" shopping in US airports? I think it would be a great idea; it would keep the airport taxes down, and give you something to do while you wait for your flight.
Not only is that the best suggestion I have ever heard, but it also makes sense, since those pre-boarding with kids are allegedly doing so to get the kids in the seats and settled, going to the back would give them time, since when the planes start to board everyone grabs the front seats.
.
