I was wondering the same thing about upgrades. Late last year as a Silver I was getting upgrades 2/3 of the time. This year as a gold I was doing ok with upgrades but lately I haven't received any (last flight was PHX-BWI and also a PHX-SFO). Usually I try to avoid flying during the busiest days.

I have a couple of RTs to PIT and BWI in the next month and if I go w/o upgrades on any of those I won't bother trying to reach platinum, especially if I keep reading about people having trouble with upgrades.

(For the domestic leg of Thursday's flight - PHX-PHL, I, of course, got the upgrade unavailable message this morning. Didn't expect my luck to change even though the guy on the phone, dealing with a separate US Airways issue, told me things looked really good for an upgrade.)