Originally Posted by
cardinal53
I will say, and I'm not the only one, that upgrades depend more on where and when you're flying than on your status. The others are right that (mainline) flights touching DFW are very hard for upgrades, so unfortunately for OP the chances of a First/Business class upgrade on that trip to SJO are slim to none.
On the other hand, though, it's fairly common for everyone on the upgrade list to clear on short regional hops not touching DFW. So if OP has another shorter trip coming up, they may well end up in First Class.
And yes, the complimentary first/business class upgrades are only for flights within North America.
I'll second this but say that I have gotten a good number of DFW upgrades. My overall upgrade rate is around 90-95%, but it is because primarily the times/days of the week I fly. I've gotten plenty of upgrades on CLT<->PHX, PHX<->SMF, GSP<->DFW, DFW<->SMF because of the scheduling, and also on shorter regional hops like GSP<->CLT. Where I haven't ever gotten upgrades is leisure travel to the Caribbean, etc. - I have been first or second on the list on these but it doesn't clear. And to be fair, I typically look at the flights I've booked about 120 hours out and those ones usually have a fully booked front cabin, so no one is getting upgraded in advance.