Oh dear... it's another one of "these" threads.

Forgive the board if you don't get the warmest Welcome to FT... But these threads get very tiresome as they crop up all too often!

I've got to presume therefore that you are SFO-based, in which case collecting miles with a British airline is going to mean you are somewhat limited, as to get to most other places via BA, you are reliant on there being SFO - LHR availability. BUT - you chose to collect with BA, and though it might seem harsh, its fair to say before amassing so many miles you really should have investigated how you could use them, likely costs and availability patterns etc...

Its untrue to say you cannot use them at all. Have you tried partner airline redemptions with AA, for example, or as the OP says with CX? And are you planning far enough ahead - I have flown to SFO and back many times on BA Miles / Avios points etc, you just need to plan ahead. Yes, it means booking months and months ahead, but hey - gives you something to look forward to. Consider using your stash of Avios points to fly internally to another BA landing point in the US first - and then searching for LHR flights from the likes of LAX, LAS, PHX etc - this will open up more opportunities.

And yes, you have to pay fuel surcharges and taxes on top of the mileage redemption, but if you are being wise and using them for J/F travel, or MFUs, then you really shouldn't be complaining about a few hundred quid in return for a seat worth several thousand pounds. It's still a bargain.

Good luck with it. Hope you find a way to make it work.