Originally Posted by
j2simpso
Interestingly my SIN -> SFO is now ticketed as a W (from a K) does that impact upgrades in any way?
Yes; you'll likely get prioritized within your status level as a W fare instead of a K. I can't speak to how likely that is to matter.
Originally Posted by
j2simpso
For instance I see in the upgrade award chart that the copay on a W fare is $550 instead of $600. Can I call UA to get that money refunded or does that happen automagically?
Sure -- you want to pay the fare difference to W first?

Gift horses and all that. I wouldn't expect to get the difference refunded. If you were to cancel and then re-request the upgrade, there's a good chance that you'd only be asked for $550, but $600 is the correct amount. You purchased a K fare; you have the rules of a K fare. The agent did you a favor by putting you into W, likely because that's easier than opening up K inventory to put you into.
Originally Posted by
j2simpso
The agent transferred my upgrade award to this updated itinerary and mentioned that around 15% of J is booked so my chances on upgrade are good
The current booking level is relatively meaningless this far out; however, you can always get the actual count from the future flight tool at
https://cablepick.net/united . Just look at the upgrade tab.