I currently (today!) live in the UK, and am relocating to Zurich but keeping an address in the UK. I am a BA silver card holder, and expect to be taken lots of flights (particularly to the UK, DUB, and SFO and NYC) from now on. Swiss appears to give better options (such as direct flights to SFO and far more options to DUB) than anything on OneWorld.

I have an existing United loyalty card (registered to a UK address) with nothing on but expired miles. Am I better off using this or using a new Swiss loyalty card (registered to a UK or ZRH address I guess)? My experience using a BA silver card on AA was pretty good (2 x free upgrades on 2 flights) but perhaps that was coincidence.