And while we are on the DFW-SIN topic, I have a related end-on-end question.

I start (tomorrow) the following end-on-end set of tickets...

Set one:

10/3 DFW-DEN-SMF
10/6 SMF-SFO
10/7 SFO-DEN-DFW

Set two:

10/4 SMF-SFO-SIN
10/6 SIN-SFO-SMF

So, here is the question:

I'm upgraded with SWUs on the second set. Any chance of getting upgrades (on the premise of stopover) with the first set of tickets.

Could I upgrade DFW-DEN-SMF (stopover) SMF-SFO-SIN? It would be three upgraded segments with a stopover of less than 24 hours.

And under a different scenario, could I upgrade SIN-SFO-SMF-SFO (stopover) SFO-DEN-DFW? This would have both a backtrack (SFO-SMF-SFO) AND a stopover of over 24 hours.

Your thoughts and experiences are greatly appreciated....