Both Swiss and NZ have excellent service and I would switch for either though I think it is unlikely you will find two seats before BMI folds diamond club (~14 days?), but if you did then definately a worthwhile switch - you can save the Avios for another day as BA isn't closing as quickly as poor old BD
I agree, unlikely I'm going to get anything by then. The only thing I think I can find is United F and even that would be via ORD. Is United F with a connection a better use of miles than keeping my BA F booking?
At a minimum though you should add on a UK domestic leg to your BA SFO return they are more of less free !
I don't understand, I live in London. Why would I want a domestic leg?