Same-day-standby is the most valuable benefit, IMO... There’s the convenience factor of standing by but it also allows you to “aribitrage” flights by booking the cheapest nonstop that day and standing by on the flight you really want... Yes, there’s a risk that you won’t get on, but typically you will...

That’s followed by MCE seat selection within 24 hours... If you’re flying lots of regional routes, the upgrades can come fairly easily too... If you’re flying hub-to-hub or really anywhere out of DFW on mainline, you don’t have much or a chance.