it worked this time
I went to the United First Class check in counter cause I did not have boarding pass yet. The agent helped me with their kiosk, which promptly offered me the $58 upgrade again. I said "Don't US Preferreds get this for free?", and she said, "Hmmm, I'll have to see what I can do". I handed her what I thought was my CP card and she gave me a funny look but kept typing on her keyboard. After a minute, I realized that I had given her my USAirways Club card (note to US - these need to look more different!), so I handed her the right card, she typed some more, and handed over my E+ boarding passes.
Had a 319 from SAT to ORD - pretty comfortable, and I appreciated the headset with audio. They also played a movie, but it was some dumb Ashton Kutcher (sp?) chick flick so I opted for my book instead. Back onto the Canadair for the ride from ORD to RDU, but only half full, so the narrower seats were just fine as I had nobody next to me.
Overall opinion of United E+, pretty decent. Nice attitudes from the staff. I'll definitely keep them in mind for places that USAirways doesn't go.