I am *gold.
My experience with confirmed same day standby, that is within 24 hrs of my originally booked flight, has been really good if the seat maps show availability, and I go to the UA club lounge and ask the rep there to make my confirmed flight change. The UA club lounge rep was able to make confirmed changes for availabilities to me that the kiosk never showed me. That UA club card has come in mighty handy.
I last did this on a United Express flight from LAS-SFO on Monday June 18. I went into the LAS UA Club lounge on Sunday June 17 to get the confirmed standby.