What you've heard may be misleading.

Southwest points are redeemed on a sliding scale totally proportional to cash cost. You can always redeem somewhere on that scale, but if the cash cost is very high, your redemption can be very high.

United has a simple chart. It costs 25000 miles to get a "controlled capacity" (aka "saver") award coach round trip within the USA, while it costs about double that to get a "last seat" (aka "standard" or "anytime") award coach round trip within the USA.

Predicting Southwest's redemption costs can be very hard. But just let it be said that while redemptions on Southwest can be much less than 25000 points sometimes for a round trip, they can also be much more than 50000 points for a round trip. So United puts limits on it and just two simple categories, while Southwest can charge just about any exact number of points (and that can constantly vary).

So if you earn United points, you know what you're shooting for best case and worst case. If you earn Southwest points, you have no idea what you're shooting for because you don't know the redemption cost until you go to redeem each time.

Having said that, using United miles (even for "saver" redemptions) for not-very-expensive-on-cash domestic coach trips is not usually a good value.. Since Southwest redemption is proportional to cost, on the other hand, it's never a better value or a worse value; it's always the same value compared to the cash price.

Finally, if you want to eventually take some longhaul international trips in business class, you can do that with United miles (once you accumulate enough of them), but you can never do that with Southwest points.


Meanwhile I agree that renting a car would be a lot better than having your parents drive 90 miles each way. In fact, car rentals with Hertz (booked on the United site) are currently a great way to earn United miles (2250 miles for a 1+ day rental in midsize or above, and btw I find midsize at Hertz to often be cost-competitive with compact at Avis).

I routinely fly Los Angeles to Nashville nonstop and then rent a car to drive two-ish hours to Huntsville (where some of my family lives), rather than making connections mid-country to Huntsville (those mid-country connections tend to be more weather-problem-plagued and take just as long for the total trip even without delays, compared to the nonstop which is only affected by weather at the origin and destination).