US Airways Dividend Miles (Pre-FlightFund Merger) - Flying standby and hoping for an upgrade

I'm flying on Monday AM from CLT to PHL (and then on to another city) and my upgrade has already cleared; however, I'd like to fly standby for an earlier flight. The earlier flight shows plenty of FC seats available. Does anyone have any tips for being sure to get not only a seat on the earlier flight (which should be no problem) but also for getting an upgrade? I am GP.

Thank you very much!

Well you are gonig to have to pay the $25 to standby (i've gotten this a lot recently). If they clear you with the $25 sometimes they will give you an F seat if they are open. Otherwise you can waitlist, but only if they clear you for a Y seat.