Thanks for that, Yes there is plenty of availability on both legs +/- 3 days which is or flexibility. BA are doing their west coast destinations for 16k Avios which is an off peak rate with no mileage charged for connecting from Newcastle, total taxes are £180. current VS rates are 21k miles from SFO with tax at £80 so with a paid connection back up from LHR total price is just over £300 each, The cheapest regular ticket in Y is around £560 each.

I think Ill go for the extra legroom twins on the A340 then.

And I suppose we`ll earn one or two VS miles back on the connecting DL and now HA rather than G4 we had considered for the return.