Originally Posted by PV_Premier

False, now that LH GPUs are electronic, they can be confirmed at the time of request if business (Y->C GPU) or first (C->F GPU) award inventory is available.

SEA/LAX/SFO->FRA C->F GPUs are probably one of the better uses of GPU that exist. Y->C isn't bad either if you get the new C.

If OP wants to go to Europe, this would be the preferred way, but can be hard to secure at booking. The most frequently available R on US->EU routes is UA metal for the early flights from ORD->FRA/LHR, and any of the hubs to BRU/AMS.

For more "exotic" destinations, don't forget that UA recently added IAH-SCL flight.

I have seen a bit of R available on the Australia flights lately too, particularly LAX-SYD.