I standby quite often coming back from PVG and Fridays are absolutely terrible. More DM's and Golds than you can imagine and the later the flight the worst it gets. As mentioned before MPC status is key for priority order for standby.

Funny standby story:

Once I went to the airport at around 2pm to board a 3pm ish flight at PVG and my flight got cancelled. He proposed that I standby for the 4pm flight and I gave the gentleman at the checkin counter an evil eye for about a second and his manager came prancing out from the back and said "Mr Chung we have a flight leaving in 10 min and I can guarantee to get you on even if you need to check your bag in."

Much to my surprise, I found myself upgraded sitting in business, having arrived at the airport 20 min earlier. I could not believe that I left my office at 1:15pm and was on a plane by 2:15pm and in Central by 5pm.