LH SEN isn't top tier any more -- LH HON is, and well worth the rather large difference (but hard to earn). Might get it next year if LH keeps improving, though I'm fairly happy with Oneworld for now. Paradoxically I've found double status in the same alliance is worth more than status in 2 different alliances (and any status below top tier is close to worthless, get more fom the fare class than from the FF status; I suppose all the comped statuses have something to do with this dilution). Of course it all depends on what you expect from an alliance and what routes you fly. The LH HON benefit of guaranteed award seat availability is terrific, actually making using those miles viable (they will convert any LH revenue seat in any fare basis into an award for you, up to 4 seats per flight with 14 days notice). If it included SQ I'd switch in a flash.