SR
even the connection in ZRH is for sure easier than LHR (after a lot of delay-problems in early summer 99).
I don't know about your mileage-account-preferences/thoughts.
(I myself don't fly SR, if I have reasonable alternatives, for personal/family-reasons I explained extensively last year on this board. I would, partly for my *Alliance-ff-program-preferences fly LH who did a pretty good job renewing their eco-seats - but still less legroom than SR).