Gold Card here, as well.

When I was a basic and silver member I never received an upgrade to F even though I flew paid C. Then again, I went from basic to silver in about 6 months. I went from silver to gold in another 6 months.

As a gold card member I have continued to fly 100% in paid C. When LAX had B744s I was upgraded 100% of the time to F with a timely phone call or two, or happened to fly during a period when BR was running a fare special. Now that BR flies B773ERs out of LAX I just buy a ticket as there are no upgrades. My primary routes are LAX-TPE-BKK-TPE-LAX and the B773ER is about all I see.

Speaking of moving up, even though I fly enough to renew gold every 12-14 months, I don't think I'll ever meet the qualifications to make Diamond. It's hard to reach that tier from the US.